Architecture & Scaling
System design with a clear focus on removing bottlenecks, defining clean data/service boundaries, and building pragmatic, step-by-step roadmaps. Actionable insights - not generic advice.
Performance • Scalability • Reliability
Software Development Engineer
Designing and building mission-critical systems that stay correct and resilient from day one - for the long run. Focus on your business - I’ll take care of architecture, scalability, and production reliability, keeping performance and stability predictable as you grow.
- 12+ years in Software Engineering & Distributed Systems
- Hands-on + Advisory: from POCs to production systems
- Solving urgent, business-critical problems
- Tackling problems others consider “impossible”
- Based in Spain, working with Europe & North America
What I Do
Software Development
Full-cycle delivery of scalable, maintainable software.
Fractional CTO / Advisory
Technical leadership without hiring a full-time CTO.
Production Reliability
Keeping systems stable, observable, and resilient in production - with fast incident response and fewer regressions.
I Build
- End-to-End Solutions Production-ready infrastructure, backend, frontend, data flows & deployment - delivered as a complete solution. Distributed systems handling high RPS and massive datasets. I build and optimize distributed architectures capable of supporting millions of users, real-time traffic, and extremely large data volumes efficiently and reliably.
- Advanced Features Complex business logic, integrations, large-scale data processing, high-complexity crawling pipelines, AI-powered features & blockchain.
- Scaling existing platforms - traffic, data, infrastructure Higher RPS, larger datasets, more users - without breaking existing functionality.
- Zero-Downtime Migrations Cross-region, multi-cloud, multi-DB data and infrastructure migrations with strict business continuity guarantees.
Case studies
A few representative examples. I can share more cases and details privately.
ML Big Data Fault Tolerance
B2B Search & Recommendation SaaS
Proposed, designed, and delivered a highly available, fault-tolerant distributed platform that provides e-commerce search and recommendations as a SaaS for online retailers—enabling faster integration, richer functionality, and higher purchase conversion rates than competing solutions.
-90%
Integration time
+30%
Purchase conversion rate
-70%
Incident rate
- 10,000 RPS peak throughput
- 300 Tb of streaming and model data
- End-to-end delivery: from data center / infrastructure configuration to client-side (frontend) integration
Migration Costs High Load
Marketplace Cross-Data Center, Cross-Stack Migration
Designed, orchestrated, and implemented a seamless migration of a distributed backend serving tens of millions of real-time users and handling hundreds of thousands of requests per second (RPS) across geographically distributed data centers.
-80%
Infrastructure costs
0% → 100%
Data locality
0 seconds
Downtime
- Canary migration with A/B testing
- Created and maintained migration documentation: guides, runbooks, and operational playbooks
- Extensive at-scale performance testing
Performance Concurrency Databases
Marketplace Discount Management System
Designed and led the development of a distributed backend and an internal dashboard to manage tens of millions of discounts, with sophisticated business rules, validations, and hundreds of parameters per discount.
-80%
Human error when creating discounts
+$200M
GMV
-$1.5M
Losses from incorrect pricing
- Heavy use of asynchronous processing, concurrency, and parallel execution
- Extensive database and storage optimization, including multi-layer caching and complex cache invalidation logic
- Dozens of sophisticated, stateful integrations with external systems
Management Scaling Efficiency
Establishing mature engineering processes and teams
Helped a startup move from “MVP spaghetti” to mature engineering processes, a clear team structure, and a maintainable, scalable architecture.
-30%
Time-to-market
-60%
Production bugs
0%
Team turnover
- Established a reliable, predictable feature delivery cadence
- Designed and led the scaling of the existing solution to handle loads orders of magnitude higher
- Introduced an on-call rotation and incident response processes, including postmortems and action-item tracking
- Improved team motivation, built a healthy engineering culture, and minimized turnover
Databases Performance High Load
Database Sharding & Performance Optimization
Reviewed the existing database configuration and load profile, identified improvement opportunities, and implemented changes without affecting business functionality.
-50%
Average query latency
-40%
Database infrastructure costs
-90%
Database-related incidents
- Designed a sharded database architecture and executed the migration
- Optimized read/write queries and implemented smart query routing between the primary and replicas based on consistency and latency requirements
- Introduced database health metrics, alerting, and an incident-response process with runbooks
Payments Concurrency Compliance
B2B Payment Gateway SaaS
Designed and implemented a distributed backend that exposes a unified card payments API across multiple payment service providers, including Stripe, Braintree, Worldpay, and others.
11
Payment providers behind a single API
-90%
Payment integration costs
100%
Payment state observability and transparency
- Asynchronous, event-driven API with concurrency-safe payment state management (idempotency, retries, and state transitions)
- Compliance-ready infrastructure aligned with security and regulatory requirements (audit logs, encryption, key management)
- Capable of handling tens of thousands of payments per second
Companies I Worked With
Tools & Technologies
Tools come and go, but strong engineering fundamentals remain. While I can quickly adapt to any stack, here are the core technologies I’ve successfully utilized to deliver results, from most to least used.
Languages
Java Kotlin Python SQL Bash JavaScript HTML CSS Rust Scala Go Groovy C# C C++ Lua
Data
PostgreSQL MySQL Kafka Hazelcast HDFS AWS S3 Cassandra Redis MapDB Elastic / OpenSearch AWS SQS MinIO ClickHouse Apache Lucene Roaring Bitmaps LMDB Oracle Keyvi
Infrastructure
Linux: administration, networking, security AWS: networking, security, high availability AWS Managed Services: ECS, RDS, MSK, Lambda, and others AWS Costs Docker / Colima AWS CloudFormation nginx Ansible Mesos Hadoop Helm Argo Kubernetes BIND 9 Apache HTTP Server
Observability
OpenTelemetry Prometheus Grafana Kibana / OpenSearch Dashboards SigNoz AWS CloudWatch PagerDuty Elastic APM Datadog
Frameworks
Spring: Core, Boot, Data, Security, and others JUnit Kotest Flask FastAPI Hibernate SQLAlchemy RxJava p5.js Spark Ktor Google Guice Backbone.js React Vue.js Django Node.js Juce CsWin32
APIs and Data Formats
REST HTTP(S) JSON SOAP XML gRPC Protobuf WebSocket SSE Avro Parquet
AI / ML / Data Science
OpenAI API RAG pandas NumPy SciPy scikit-learn Keras
Design
C4 UML Figma TDD DDD
About
I’ve spent most of my career working on systems where performance, reliability, and predictable delivery matter. I work as both a Software Engineer and Tech Lead, and stay hands-on: understanding the problem, making architectural decisions, and getting the result into production.
My main area of expertise is high-load distributed systems and complex migrations. I’m often brought in to solve difficult technical problems, scale existing systems, provide an experienced pair of eyes on important decisions, make sure a system works reliably from day one, or handle challenges that seem unsolvable.
I speak English, Spanish, and Russian, effectively bridging the gap between business goals and technical execution for teams of any size.
Why Work With Me (Not Just Another Freelancer)
Industrial-grade systems
If software were construction, I wouldn’t build sheds - I build factories, power plants, and tunnels. My systems are engineered for longevity, reliability, and scale.
Fully Committed
I stay with you through the entire lifecycle—from problem discovery to stable production. I am present and accessible when reliability truly matters.
Navigating the "impossible"
Even when the original idea seems technically impossible, I analyze underlying business constraints to find alternative strategies and deliver a clear path forward.
How I Work
- Conduct a rapid audit of goals, constraints, and risks.
- Prioritize changes that drive core business value and mitigate risks first.
- Document decisions clearly via RFCs to keep scope realistic.
- Deliver sustainable improvements your team can maintain without me.
Good Fit If You Need
- Resolution for scaling bottlenecks and performance regressions.
- Incident reduction and a healthier on-call environment.
- A breakthrough on complex engineering problems your team considers impossible.
- Architecture cleanup without a massive, risky rewrite.
- Advisory support and technical mentorship for a growing team.
