Backend Systems & High-Load Architecture

Engineered for scale. Designed for reliability. Proven under real-world load.

We design backend systems that handle massive traffic, real-time processing, and enterprise-level complexity — without breaking, slowing down, or needing to be rewritten. Our architectures power fintech, telecom, SaaS, marketplaces, analytics platforms, and products where stability and performance are mission-critical.

What We Build

High-load, fault-tolerant, and scalable backend systems:

  • event-driven architectures
  • systems that process millions of events per second
  • real-time platforms (WebSockets, Kafka, streaming pipelines)
  • microservices and distributed systems
  • high-performance APIs for mobile & web
  • backend cores for SaaS & enterprise products
  • fault-tolerant infrastructure with autoscaling
  • big-data ingestion and processing systems

Problems We Solve

We work with companies that cannot afford downtime, delays, or instability:

  • slow or unstable API under load
  • performance drops at scale
  • architecture that cannot grow with the product
  • latency issues & throughput limitations
  • overloaded or misconfigured databases
  • lack of observability (no metrics, logs, alerts)
  • monolithic codebases that block progress
  • risky deployments & unexpected failures
  • real-time features that don't work reliably
  • technical debt that becomes too expensive

Our Solutions

High-Load Architecture

Systems built for millions of users and extreme concurrency.

  • Event-Driven Architecture (EDA)
  • DDD / CQRS patterns
  • Horizontal scaling
  • Resilient messaging layers

Real-Time Platforms

Processing events in milliseconds.

  • WebSockets
  • Kafka Streams
  • gRPC / WebRTC
  • Pub/Sub communication models

Enterprise-Grade Backend

Clean engineering, predictable behavior.

  • modular & domain-driven architecture
  • strict API contracts
  • zero-downtime deployments
  • versioned APIs & compatibility layers

Databases & Storage Optimization

Built for speed, consistency, and massive data volumes.

  • PostgreSQL (optimized for scale)
  • ClickHouse (analytics & event storage)
  • Redis (in-memory computation)
  • partitioning, sharding, replication

What You Get

01

A system that scales without rewriting

Architectures designed for long-term growth — not short-term patches.

02

Real-time performance under heavy load

Optimized pipelines that stay fast at peak hours.

03

Zero-downtime reliability

Failover, auto-recovery, and observability built into the core.

04

Clean, maintainable engineering

Avoid technical debt that slows teams down.

05

Infrastructure that grows with your product

Containers, orchestration, monitoring, and automation pre-configured.

Technology Stack

Enterprise-proven tools we use daily:

Languages

Java 17/20KotlinTypeScriptGo

Frameworks

Spring BootMicronautKtorVert.x

Messaging / Streaming

Apache KafkaRabbitMQKafka Streams

Databases

PostgreSQLClickHouseMongoDBRedis

Cloud & DevOps

KubernetesDockerTerraformGitHub ActionsPrometheusGrafanaELK Stack

Who This Service Is For

  • fintech platforms
  • SaaS products
  • telecom & messaging systems
  • marketplaces & aggregators
  • analytics & data-heavy platforms
  • real-time consumer products
  • multi-region and high-traffic apps

Industry Applications

We design and operate high-load systems used in:

  • Fintech platforms (payments, trading, KYC, compliance)
  • SaaS products with real-time dashboards and collaboration
  • Marketplaces and high-traffic consumer applications
  • Analytics and reporting platforms processing billions of events
  • Streaming and event-driven systems (media, gaming, IoT)

Frequently Asked Questions

How do you design for millions of events per second?

We combine event-driven architecture, Apache Kafka for high-throughput message streaming, horizontally scalable microservices, and optimized database layers. Systems are designed with CQRS patterns, outbox patterns for consistency, and careful partitioning to distribute load across multiple nodes. Load testing validates performance before production deployment.

What latency can Kafka-based pipelines achieve?

With proper architecture, Kafka pipelines can achieve end-to-end latency under 10ms for most use cases. We optimize consumer groups, use Kafka Streams for stateful processing, implement efficient serialization, and minimize network hops. For ultra-low latency requirements, we use in-memory processing with Redis and direct database connections.

How to avoid backpressure collapse?

We implement circuit breakers, rate limiting, graceful degradation, and backpressure handling at multiple layers. Kafka consumer groups are configured with appropriate fetch sizes and processing rates. Downstream services use queues and buffering to handle spikes. Monitoring and alerting catch issues before they cascade.

How to scale Spring Boot APIs?

We design stateless services that can scale horizontally, use connection pooling, implement caching layers (Redis), optimize database queries, and use load balancers. Kubernetes autoscaling adjusts pod count based on CPU, memory, and custom metrics. Database read replicas distribute query load.

What's the difference between microservices and monolith for high-load?

Microservices allow independent scaling of components (e.g., payment processing vs. analytics), better fault isolation, and technology diversity. However, they add complexity. We evaluate based on team size, traffic patterns, and business requirements. For many high-load systems, a modular monolith with clear boundaries can be more maintainable initially, with migration to microservices as needed.

Get Started

We'll analyze your current infrastructure, performance bottlenecks, and scalability risks — and propose the right architecture for your next stage of growth. Let's build a system that never slows down.

Talk to the team

H-Studio provides high-load backend development and system architecture services for companies across Europe. We design and implement backend systems that handle millions of events per second, process real-time data streams, and scale horizontally to support enterprise-level traffic. Our team specializes in event-driven architectures, microservices, distributed systems, and high-performance APIs built with Java, Kotlin, Spring Boot, Apache Kafka, PostgreSQL, and ClickHouse.

We work with fintech platforms, SaaS products, marketplaces, analytics platforms, and real-time consumer applications that require zero-downtime reliability, predictable performance under load, and long-term maintainability. Our backend engineering services include architecture design, performance optimization, database tuning, infrastructure setup, and ongoing maintenance — from first MVP to enterprise-scale deployments.