☕ 🌐 Distributed Systems with TuskLang Java

Java Documentation

🌐 Distributed Systems with TuskLang Java

"We don't bow to any king" - Distributed Java Edition

TuskLang Java enables building robust distributed systems with microservices, event-driven architecture, and distributed patterns that scale across multiple nodes and services.

🎯 Distributed Architecture Overview

Microservices Configuration

// distributed-app.tsk
[distributed_system]
name: "Enterprise Distributed App"
version: "3.0.0"
deployment_mode: "microservices"

[service_mesh] type: "istio" enabled: true tracing: true metrics: true security: { mTLS: true authorization: true }

[services] user_service: { name: "user-service" port: 8081 replicas: 3 health_check: "/health" dependencies: ["database", "cache"] api_version: "v1" rate_limit: { requests_per_minute: 1000 burst_size: 100 } }

order_service: { name: "order-service" port: 8082 replicas: 5 health_check: "/health" dependencies: ["database", "payment_service", "inventory_service"] api_version: "v1" circuit_breaker: { failure_threshold: 5 recovery_timeout: "30s" half_open_state: true } }

payment_service: { name: "payment-service" port: 8083 replicas: 2 health_check: "/health" dependencies: ["database", "external_payment_gateway"] api_version: "v1" retry_policy: { max_attempts: 3 backoff: "exponential" initial_delay: "1s" } }

inventory_service: { name: "inventory-service" port: 8084 replicas: 3 health_check: "/health" dependencies: ["database", "cache"] api_version: "v1" cache_strategy: { ttl: "5m" invalidation: "write_through" } }

[databases] primary: { type: "postgresql" host: @env("DB_HOST", "localhost") port: @env("DB_PORT", "5432") name: @env("DB_NAME", "distributed_app") user: @env("DB_USER", "app_user") password: @env.secure("DB_PASSWORD") pool_size: 50 read_replicas: [ { host: @env("DB_READ_REPLICA_1", "read-replica-1") port: @env("DB_PORT", "5432") weight: 0.5 }, { host: @env("DB_READ_REPLICA_2", "read-replica-2") port: @env("DB_PORT", "5432") weight: 0.5 } ] }

cache: { type: "redis" mode: "cluster" nodes: [ { host: @env("REDIS_NODE_1", "redis-node-1") port: @env("REDIS_PORT", "6379") }, { host: @env("REDIS_NODE_2", "redis-node-2") port: @env("REDIS_PORT", "6379") }, { host: @env("REDIS_NODE_3", "redis-node-3") port: @env("REDIS_PORT", "6379") } ] password: @env.secure("REDIS_PASSWORD") ttl: "1h" max_memory: "2gb" }

[message_broker] type: "kafka" bootstrap_servers: [ @env("KAFKA_BROKER_1", "kafka-1:9092"), @env("KAFKA_BROKER_2", "kafka-2:9092"), @env("KAFKA_BROKER_3", "kafka-3:9092") ] security: { sasl_mechanism: "PLAIN" username: @env.secure("KAFKA_USERNAME") password: @env.secure("KAFKA_PASSWORD") } topics: { user_events: { partitions: 10 replication_factor: 3 retention: "7d" } order_events: { partitions: 20 replication_factor: 3 retention: "30d" } payment_events: { partitions: 15 replication_factor: 3 retention: "90d" } }

[distributed_tracing] enabled: true sampling_rate: 0.1 exporter: "jaeger" endpoint: @env("JAEGER_ENDPOINT", "http://jaeger:14268/api/traces") correlation_id_header: "X-Correlation-ID"

🔄 Event-Driven Architecture

Event Configuration

// events.tsk
[event_schema]
version: "1.0"
namespace: "com.enterprise.events"

[events] user_created: { type: "user.created" version: "1.0" schema: { user_id: "string" email: "string" first_name: "string" last_name: "string" created_at: "timestamp" metadata: "object" } producers: ["user_service"] consumers: ["notification_service", "analytics_service", "audit_service"] routing_key: "user.created" dead_letter_queue: "user_events_dlq" }

user_updated: { type: "user.updated" version: "1.0" schema: { user_id: "string" email: "string" first_name: "string" last_name: "string" updated_at: "timestamp" changes: "array" metadata: "object" } producers: ["user_service"] consumers: ["notification_service", "analytics_service", "audit_service"] routing_key: "user.updated" dead_letter_queue: "user_events_dlq" }

order_created: { type: "order.created" version: "1.0" schema: { order_id: "string" user_id: "string" items: "array" total_amount: "decimal" currency: "string" status: "string" created_at: "timestamp" metadata: "object" } producers: ["order_service"] consumers: ["payment_service", "inventory_service", "notification_service", "analytics_service"] routing_key: "order.created" dead_letter_queue: "order_events_dlq" }

order_status_changed: { type: "order.status.changed" version: "1.0" schema: { order_id: "string" user_id: "string" old_status: "string" new_status: "string" changed_at: "timestamp" reason: "string" metadata: "object" } producers: ["order_service", "payment_service", "inventory_service"] consumers: ["notification_service", "analytics_service", "audit_service"] routing_key: "order.status.changed" dead_letter_queue: "order_events_dlq" }

payment_processed: { type: "payment.processed" version: "1.0" schema: { payment_id: "string" order_id: "string" user_id: "string" amount: "decimal" currency: "string" status: "string" gateway: "string" processed_at: "timestamp" metadata: "object" } producers: ["payment_service"] consumers: ["order_service", "notification_service", "analytics_service", "audit_service"] routing_key: "payment.processed" dead_letter_queue: "payment_events_dlq" }

[event_handlers] user_service: { handlers: [ { event_type: "order.created" handler: "handleOrderCreated" async: true retry_policy: { max_attempts: 3 backoff: "exponential" } }, { event_type: "payment.processed" handler: "handlePaymentProcessed" async: true retry_policy: { max_attempts: 3 backoff: "exponential" } } ] }

order_service: { handlers: [ { event_type: "payment.processed" handler: "handlePaymentProcessed" async: false retry_policy: { max_attempts: 5 backoff: "exponential" } }, { event_type: "inventory.updated" handler: "handleInventoryUpdated" async: true retry_policy: { max_attempts: 3 backoff: "exponential" } } ] }

Event-Driven Service Implementation

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Bean;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.stereotype.Service;
import org.tusklang.java.annotations.TuskConfig;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.util.Map;

@Configuration @TuskConfig public class EventDrivenConfig { @Bean public ObjectMapper eventObjectMapper() { ObjectMapper mapper = new ObjectMapper(); mapper.registerModule(new JavaTimeModule()); return mapper; } @Bean public EventPublisher eventPublisher(KafkaTemplate<String, String> kafkaTemplate, ObjectMapper objectMapper) { return new EventPublisher(kafkaTemplate, objectMapper); } @Bean public EventHandlerRegistry eventHandlerRegistry() { return new EventHandlerRegistry(); } }

@Service public class EventPublisher { private final KafkaTemplate<String, String> kafkaTemplate; private final ObjectMapper objectMapper; private final Map<String, EventConfig> eventConfigs; public EventPublisher(KafkaTemplate<String, String> kafkaTemplate, ObjectMapper objectMapper, Map<String, EventConfig> eventConfigs) { this.kafkaTemplate = kafkaTemplate; this.objectMapper = objectMapper; this.eventConfigs = eventConfigs; } public <T> void publishEvent(String eventType, T event) { try { EventConfig config = eventConfigs.get(eventType); if (config == null) { throw new EventConfigurationException("No configuration found for event: " + eventType); } String eventJson = objectMapper.writeValueAsString(event); String topic = config.getTopic(); String routingKey = config.getRoutingKey(); kafkaTemplate.send(topic, routingKey, eventJson) .addCallback( result -> log.info("Event published successfully: {}", eventType), ex -> log.error("Failed to publish event: {}", eventType, ex) ); } catch (Exception e) { log.error("Error publishing event: {}", eventType, e); throw new EventPublishException("Failed to publish event: " + eventType, e); } } public <T> void publishEventWithCorrelation(String eventType, T event, String correlationId) { try { EventConfig config = eventConfigs.get(eventType); if (config == null) { throw new EventConfigurationException("No configuration found for event: " + eventType); } // Add correlation ID to event metadata if (event instanceof BaseEvent) { ((BaseEvent) event).setCorrelationId(correlationId); } String eventJson = objectMapper.writeValueAsString(event); String topic = config.getTopic(); String routingKey = config.getRoutingKey(); kafkaTemplate.send(topic, routingKey, eventJson) .addCallback( result -> log.info("Event published successfully: {} with correlation: {}", eventType, correlationId), ex -> log.error("Failed to publish event: {} with correlation: {}", eventType, correlationId, ex) ); } catch (Exception e) { log.error("Error publishing event: {} with correlation: {}", eventType, correlationId, e); throw new EventPublishException("Failed to publish event: " + eventType, e); } } }

@Service public class UserEventHandlers { private final EventPublisher eventPublisher; private final UserService userService; public UserEventHandlers(EventPublisher eventPublisher, UserService userService) { this.eventPublisher = eventPublisher; this.userService = userService; } @KafkaListener(topics = "order_events", groupId = "user_service") public void handleOrderCreated(String eventJson) { try { OrderCreatedEvent event = objectMapper.readValue(eventJson, OrderCreatedEvent.class); // Update user's order history userService.addOrderToHistory(event.getUserId(), event.getOrderId()); // Publish user updated event UserUpdatedEvent userEvent = new UserUpdatedEvent(); userEvent.setUserId(event.getUserId()); userEvent.setUpdatedAt(Instant.now()); userEvent.setChanges(Arrays.asList("order_history")); eventPublisher.publishEvent("user.updated", userEvent); } catch (Exception e) { log.error("Error handling order created event", e); // Send to dead letter queue sendToDeadLetterQueue("order_events_dlq", eventJson, e); } } @KafkaListener(topics = "payment_events", groupId = "user_service") public void handlePaymentProcessed(String eventJson) { try { PaymentProcessedEvent event = objectMapper.readValue(eventJson, PaymentProcessedEvent.class); // Update user's payment history userService.addPaymentToHistory(event.getUserId(), event.getPaymentId()); // Publish user updated event UserUpdatedEvent userEvent = new UserUpdatedEvent(); userEvent.setUserId(event.getUserId()); userEvent.setUpdatedAt(Instant.now()); userEvent.setChanges(Arrays.asList("payment_history")); eventPublisher.publishEvent("user.updated", userEvent); } catch (Exception e) { log.error("Error handling payment processed event", e); // Send to dead letter queue sendToDeadLetterQueue("payment_events_dlq", eventJson, e); } } private void sendToDeadLetterQueue(String dlqTopic, String eventJson, Exception error) { DeadLetterEvent dlqEvent = new DeadLetterEvent(); dlqEvent.setOriginalEvent(eventJson); dlqEvent.setError(error.getMessage()); dlqEvent.setTimestamp(Instant.now()); kafkaTemplate.send(dlqTopic, eventJson) .addCallback( result -> log.info("Event sent to DLQ: {}", dlqTopic), ex -> log.error("Failed to send event to DLQ: {}", dlqTopic, ex) ); } }

🔗 Service Communication Patterns

Circuit Breaker Configuration

// circuit-breaker.tsk
[circuit_breaker]
default_config: {
    failure_threshold: 5
    recovery_timeout: "30s"
    half_open_state: true
    monitoring: true
}

[services] payment_service: { failure_threshold: 3 recovery_timeout: "60s" half_open_state: true exceptions: ["PaymentGatewayException", "NetworkException"] }

inventory_service: { failure_threshold: 10 recovery_timeout: "15s" half_open_state: false exceptions: ["DatabaseException"] }

external_api: { failure_threshold: 2 recovery_timeout: "120s" half_open_state: true exceptions: ["HttpClientException", "TimeoutException"] }

[monitoring] metrics: { enabled: true circuit_state_changes: true failure_counts: true success_counts: true response_times: true }

alerts: { circuit_open: { enabled: true threshold: 1 notification: { email: ["devops@company.com"] slack: "#alerts" } } }

Circuit Breaker Implementation

import io.github.resilience4j.circuitbreaker.CircuitBreaker;
import io.github.resilience4j.circuitbreaker.CircuitBreakerConfig;
import io.github.resilience4j.circuitbreaker.CircuitBreakerRegistry;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.tusklang.java.annotations.TuskConfig;
import java.time.Duration;

@Configuration @TuskConfig public class CircuitBreakerConfiguration { private final Map<String, CircuitBreakerConfig> circuitBreakerConfigs; public CircuitBreakerConfiguration(Map<String, CircuitBreakerConfig> circuitBreakerConfigs) { this.circuitBreakerConfigs = circuitBreakerConfigs; } @Bean public CircuitBreakerRegistry circuitBreakerRegistry() { CircuitBreakerRegistry registry = CircuitBreakerRegistry.ofDefaults(); // Register circuit breakers for each service circuitBreakerConfigs.forEach((serviceName, config) -> { CircuitBreaker circuitBreaker = CircuitBreaker.of(serviceName, config); registry.addConfiguration(serviceName, config); }); return registry; } @Bean public CircuitBreakerService circuitBreakerService(CircuitBreakerRegistry registry) { return new CircuitBreakerService(registry); } }

@Service public class CircuitBreakerService { private final CircuitBreakerRegistry registry; private final Map<String, CircuitBreakerConfig> configs; public CircuitBreakerService(CircuitBreakerRegistry registry, Map<String, CircuitBreakerConfig> configs) { this.registry = registry; this.configs = configs; } public <T> T executeWithCircuitBreaker(String serviceName, Supplier<T> supplier) { CircuitBreaker circuitBreaker = registry.circuitBreaker(serviceName); return circuitBreaker.executeSupplier(supplier); } public void executeWithCircuitBreaker(String serviceName, Runnable runnable) { CircuitBreaker circuitBreaker = registry.circuitBreaker(serviceName); circuitBreaker.executeRunnable(runnable); } public CircuitBreaker.State getCircuitState(String serviceName) { CircuitBreaker circuitBreaker = registry.circuitBreaker(serviceName); return circuitBreaker.getState(); } public CircuitBreaker.Metrics getCircuitMetrics(String serviceName) { CircuitBreaker circuitBreaker = registry.circuitBreaker(serviceName); return circuitBreaker.getMetrics(); } }

@Service public class PaymentServiceClient { private final CircuitBreakerService circuitBreakerService; private final RestTemplate restTemplate; private final String paymentServiceUrl; public PaymentServiceClient(CircuitBreakerService circuitBreakerService, RestTemplate restTemplate, @Value("${payment.service.url}") String paymentServiceUrl) { this.circuitBreakerService = circuitBreakerService; this.restTemplate = restTemplate; this.paymentServiceUrl = paymentServiceUrl; } public PaymentResponse processPayment(PaymentRequest request) { return circuitBreakerService.executeWithCircuitBreaker("payment_service", () -> { try { ResponseEntity<PaymentResponse> response = restTemplate.postForEntity( paymentServiceUrl + "/payments", request, PaymentResponse.class ); if (response.getStatusCode().is2xxSuccessful()) { return response.getBody(); } else { throw new PaymentServiceException("Payment service returned error: " + response.getStatusCode()); } } catch (Exception e) { log.error("Error calling payment service", e); throw new PaymentServiceException("Failed to process payment", e); } }); } public PaymentStatus getPaymentStatus(String paymentId) { return circuitBreakerService.executeWithCircuitBreaker("payment_service", () -> { try { ResponseEntity<PaymentStatus> response = restTemplate.getForEntity( paymentServiceUrl + "/payments/" + paymentId + "/status", PaymentStatus.class ); if (response.getStatusCode().is2xxSuccessful()) { return response.getBody(); } else { throw new PaymentServiceException("Payment service returned error: " + response.getStatusCode()); } } catch (Exception e) { log.error("Error getting payment status", e); throw new PaymentServiceException("Failed to get payment status", e); } }); } }

🔄 Distributed Caching

Cache Configuration

// cache.tsk
[distributed_cache]
type: "redis"
mode: "cluster"
nodes: [
    {
        host: @env("REDIS_NODE_1", "redis-node-1")
        port: @env("REDIS_PORT", "6379")
        weight: 1
    },
    {
        host: @env("REDIS_NODE_2", "redis-node-2")
        port: @env("REDIS_PORT", "6379")
        weight: 1
    },
    {
        host: @env("REDIS_NODE_3", "redis-node-3")
        port: @env("REDIS_PORT", "6379")
        weight: 1
    }
]
password: @env.secure("REDIS_PASSWORD")
max_memory: "4gb"
eviction_policy: "allkeys-lru"

[cache_strategies] user_cache: { ttl: "1h" max_size: 10000 invalidation: "write_through" compression: true serialization: "json" }

order_cache: { ttl: "30m" max_size: 5000 invalidation: "write_behind" compression: true serialization: "json" }

product_cache: { ttl: "24h" max_size: 20000 invalidation: "cache_aside" compression: true serialization: "json" }

session_cache: { ttl: "2h" max_size: 1000 invalidation: "write_through" compression: false serialization: "binary" }

[cache_events] user_updated: { cache_key: "user:{user_id}" invalidation: true propagation: true }

order_created: { cache_key: "user_orders:{user_id}" invalidation: false propagation: true }

product_updated: { cache_key: "product:{product_id}" invalidation: true propagation: true }

Distributed Cache Implementation

import org.springframework.cache.annotation.Cacheable;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;
import org.tusklang.java.annotations.TuskConfig;
import java.util.concurrent.TimeUnit;

@Configuration @TuskConfig public class CacheConfiguration { @Bean public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) { RedisTemplate<String, Object> template = new RedisTemplate<>(); template.setConnectionFactory(connectionFactory); // Configure serialization template.setKeySerializer(new StringRedisSerializer()); template.setValueSerializer(new GenericJackson2JsonRedisSerializer()); template.setHashKeySerializer(new StringRedisSerializer()); template.setHashValueSerializer(new GenericJackson2JsonRedisSerializer()); return template; } @Bean public CacheManager cacheManager(RedisTemplate<String, Object> redisTemplate, Map<String, CacheStrategy> cacheStrategies) { RedisCacheManager cacheManager = RedisCacheManager.builder(redisTemplate.getConnectionFactory()) .cacheDefaults(RedisCacheConfiguration.defaultCacheConfig() .entryTtl(Duration.ofHours(1)) .serializeKeysWith(RedisSerializationContext.SerializationPair .fromSerializer(new StringRedisSerializer())) .serializeValuesWith(RedisSerializationContext.SerializationPair .fromSerializer(new GenericJackson2JsonRedisSerializer()))) .build(); // Configure custom cache settings cacheStrategies.forEach((cacheName, strategy) -> { RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig() .entryTtl(Duration.parse(strategy.getTtl())) .serializeKeysWith(RedisSerializationContext.SerializationPair .fromSerializer(new StringRedisSerializer())) .serializeValuesWith(RedisSerializationContext.SerializationPair .fromSerializer(new GenericJackson2JsonRedisSerializer())); cacheManager.setCacheConfiguration(cacheName, config); }); return cacheManager; } }

@Service public class DistributedCacheService { private final RedisTemplate<String, Object> redisTemplate; private final Map<String, CacheStrategy> cacheStrategies; private final EventPublisher eventPublisher; public DistributedCacheService(RedisTemplate<String, Object> redisTemplate, Map<String, CacheStrategy> cacheStrategies, EventPublisher eventPublisher) { this.redisTemplate = redisTemplate; this.cacheStrategies = cacheStrategies; this.eventPublisher = eventPublisher; } public <T> T get(String cacheName, String key, Class<T> type) { String fullKey = buildCacheKey(cacheName, key); Object value = redisTemplate.opsForValue().get(fullKey); if (value != null) { log.debug("Cache hit for key: {}", fullKey); return type.cast(value); } log.debug("Cache miss for key: {}", fullKey); return null; } public void put(String cacheName, String key, Object value) { String fullKey = buildCacheKey(cacheName, key); CacheStrategy strategy = cacheStrategies.get(cacheName); if (strategy != null) { redisTemplate.opsForValue().set(fullKey, value, Duration.parse(strategy.getTtl())); } else { redisTemplate.opsForValue().set(fullKey, value); } log.debug("Cached value for key: {}", fullKey); // Publish cache event if configured publishCacheEvent(cacheName, key, "PUT"); } public void evict(String cacheName, String key) { String fullKey = buildCacheKey(cacheName, key); redisTemplate.delete(fullKey); log.debug("Evicted cache for key: {}", fullKey); // Publish cache event if configured publishCacheEvent(cacheName, key, "EVICT"); } public void evictPattern(String cacheName, String pattern) { String fullPattern = buildCacheKey(cacheName, pattern); Set<String> keys = redisTemplate.keys(fullPattern); if (keys != null && !keys.isEmpty()) { redisTemplate.delete(keys); log.debug("Evicted {} cache entries for pattern: {}", keys.size(), fullPattern); } } private String buildCacheKey(String cacheName, String key) { return String.format("%s:%s", cacheName, key); } private void publishCacheEvent(String cacheName, String key, String operation) { CacheEvent event = new CacheEvent(); event.setCacheName(cacheName); event.setKey(key); event.setOperation(operation); event.setTimestamp(Instant.now()); eventPublisher.publishEvent("cache.operation", event); } }

@Service public class UserService { private final DistributedCacheService cacheService; private final UserRepository userRepository; public UserService(DistributedCacheService cacheService, UserRepository userRepository) { this.cacheService = cacheService; this.userRepository = userRepository; } @Cacheable(value = "user_cache", key = "#userId") public User getUserById(String userId) { log.debug("Fetching user from database: {}", userId); return userRepository.findById(userId) .orElseThrow(() -> new UserNotFoundException("User not found: " + userId)); } @CachePut(value = "user_cache", key = "#user.id") public User createUser(User user) { log.debug("Creating new user: {}", user.getId()); User savedUser = userRepository.save(user); // Publish user created event UserCreatedEvent event = new UserCreatedEvent(); event.setUserId(savedUser.getId()); event.setEmail(savedUser.getEmail()); event.setCreatedAt(Instant.now()); eventPublisher.publishEvent("user.created", event); return savedUser; } @CachePut(value = "user_cache", key = "#user.id") public User updateUser(User user) { log.debug("Updating user: {}", user.getId()); User updatedUser = userRepository.save(user); // Publish user updated event UserUpdatedEvent event = new UserUpdatedEvent(); event.setUserId(updatedUser.getId()); event.setUpdatedAt(Instant.now()); event.setChanges(Arrays.asList("profile", "preferences")); eventPublisher.publishEvent("user.updated", event); return updatedUser; } @CacheEvict(value = "user_cache", key = "#userId") public void deleteUser(String userId) { log.debug("Deleting user: {}", userId); userRepository.deleteById(userId); // Publish user deleted event UserDeletedEvent event = new UserDeletedEvent(); event.setUserId(userId); event.setDeletedAt(Instant.now()); eventPublisher.publishEvent("user.deleted", event); } }

🔧 Best Practices

1. Service Communication

- Use circuit breakers for resilience - Implement retry policies with exponential backoff - Use health checks for service discovery - Implement proper timeout handling

2. Event-Driven Architecture

- Use event sourcing for audit trails - Implement CQRS for read/write separation - Use saga pattern for distributed transactions - Implement dead letter queues for failed events

3. Distributed Caching

- Use cache-aside pattern for read-heavy workloads - Implement write-through for consistency - Use cache invalidation strategies - Monitor cache hit rates and performance

4. Monitoring and Observability

- Use distributed tracing for request tracking - Implement health checks for all services - Use structured logging with correlation IDs - Monitor circuit breaker states and metrics

5. Security

- Use mTLS for service-to-service communication - Implement proper authentication and authorization - Use secure configuration management - Monitor for security events

🎯 Summary

TuskLang Java distributed systems provide:

- Microservices Architecture: Service discovery, load balancing, and health checks - Event-Driven Communication: Kafka integration with event schemas and handlers - Circuit Breakers: Resilience patterns with monitoring and alerts - Distributed Caching: Redis cluster with multiple cache strategies - Service Mesh Integration: Istio support for advanced traffic management

The combination of TuskLang's executable configuration with Java's distributed systems capabilities creates a powerful platform for building scalable, resilient, and maintainable microservices.

"We don't bow to any king" - Build distributed systems that scale with confidence!