Backend Systems Built to Stay in Production
I design and build the APIs, databases, and backend services that a business runs on. One architect, directly accountable for the system — no account managers, no handoffs, no layers between your problem and the person solving it.
- National-scale ERP running in production, maintained for years
- Public-sector governance platform
- Open source Laravel package, publicly maintained
Engineered for Performance
Focused expertise in the parts of the stack where systems actually fail
API Architecture & Development
Design and build RESTful, GraphQL, and real-time APIs. Optimized for performance, security, and the developers who have to consume them.
Software Architecture
Strategic system design from the ground up. Microservices, monoliths, serverless — I pick the architecture that matches your business requirements and your team's size, not the one that reads best in a slide deck.
Database Engineering
PostgreSQL, MySQL, NoSQL design and optimization. Data layers that handle growth without breaking: query optimization, indexing strategies, and replication architecture.
Backend Development
Modern PHP and Node.js development with Laravel, Symfony, Express, and NestJS. Clean code, real test coverage, and deployment pipelines included.
System Integration
Connecting systems that were never designed to talk to each other. Third-party API integration, legacy modernization, and data synchronization across platforms.
Technical Consulting
Architecture reviews, performance audits, security assessments. A second opinion from someone who has had to live with these decisions long-term.
Modern Tools, Proven Results
The stack I work in day to day
Backend Languages
- PHP 8.x
- Node.js
- TypeScript
- JavaScript (ES6+)
Databases
- PostgreSQL
- MySQL / MariaDB
- MongoDB
- Redis
Frameworks
- Laravel
- Symfony
- Express.js
- NestJS
API & Integration
- REST Architecture
- GraphQL
- WebSockets
- gRPC
Infrastructure
- AWS / Cloud Services
- Docker & Containers
- Kubernetes
- CI/CD Pipelines
Networking
- TCP/IP Stack
- Load Balancing
- CDN Integration
- Network Security
Eternia Solutions LLC
Eternia Solutions is a one-person consultancy. I'm Simo Jaković — the architect, the engineer, and the person who answers the phone.
That is deliberate. On the work I take, the value is in one engineer who understands the whole system and stays accountable for it: the schema, the API contract, the deployment, and the incident three months after launch. You are not handed to a junior after the sales call, because there is no sales call and no junior.
My background is backend and infrastructure — enterprise resource planning, public-sector governance systems, and the integrations that hold them together. Systems that people are contractually obliged to use every working day, where downtime is a phone call and a bad schema decision follows you for years.
I don't do surface-level implementations, and I take a limited number of clients at a time so each one gets real attention. If you're launching a product, scaling a platform, or untangling a legacy system, I bring 15+ years of hands-on experience with exactly those problems.
Eternia Solutions LLC is registered in Wyoming, USA. I work from Belgrade, Serbia, on Central European Time, which overlaps the US Eastern morning most of the working day.