Backend Engineer

Backend Engineer

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About Weltrade
Weltrade is a leading international Fintech innovator with over two decades of stability and trust. Established in 2006, we are committed to providing secure, efficient, and accessible trading solutions in the global FX and online trading market. We operate as a truly global, remote-first team across different time zones, united by a culture of autonomy and shared goals. We are currently seeking proactive specialists to join our cross-functional environment. At Weltrade, we offer impact, ownership, and the stability to do your best work. We are a flat organization where empowered professionals are trusted to design the future of global trading.

About Role:
You'll join the product engineering team. Your mission is to build predictable, auditable, and resilient domain services while modernizing legacy code safely and incrementally. The core challenge is shipping new features and improving architecture without disrupting live traffic, financial calculations, or user trust - here, a small change in logic can turn into a costly mistake.

You're expected to dive deep into the business side of any domain. The requirement - versatility and the ability to quickly grasp new business logic - is mandatory.

You'll have direct ownership over features end-to-end, close collaboration with QA, and use of modern AI tools to move faster without compromising on quality.

What makes this Role different:

• You own features end-to-end: design, code, tests, observability, post-release monitoring.

• You don't toss code over the wall to QA - you work with testers from day one, write integration tests yourself, and treat regressions in your code as personal responsibility.

• You use AI as a force multiplier, not a substitute for thinking. We expect you to ship more with AI tooling - but to critically review every line that goes to production.

• You work with real legacy code with MariaDB and help gradually carve out clean Symfony services from it without breaking what works.

• You ramp up quickly in unfamiliar business domains - sit down with a product manager or tech lead, extract the data model, key rules, edge cases. You don't wait to be spoon-fed.

Requirements:

• 5+ years of commercial PHP experience with production-grade ownership: shipping, supporting, and improving live systems with real users and real money

• PHP 8.1+ and Symfony in production - DI, Doctrine, async messaging

• Strong SQL on MariaDB/MySQL under load: query plans, index design, optimizing queries against tables with hundreds of millions of rows. Comfortable beyond basic EXPLAIN

• Third-party API integration experience (REST/webhooks): authentication, retries, idempotency, error handling, contract tests at boundaries

• Test discipline: writing PHPUnit unit and integration tests as part of every feature, not after; comfortable mocking external dependencies and designing code for testability

• Static analysis in your daily workflow: PHPStan or Psalm at level 6+, treating warnings as errors

• Hands-on legacy modernization - keeping business logic stable while gradually replacing internals; experience with strangler-fig pattern or equivalent

• AI tools in active use - Claude Code, Cursor, Copilot, or similar. Comfortable using them to accelerate refactoring, generate test scaffolding, and analyze unfamiliar code, while critically reviewing output and rejecting bad suggestions

• Ability to ramp up in new business domains quickly - comfortable moving between domains (payments, KYC, trading, partnerships, back-office) and becoming productive in any of them within 1–2 weeks

Strongly preferred

• FinTech, payments, or regulated industry background

• Event-driven architecture: Kafka, NATS, RabbitMQ, or similar message brokers

• Experience modernizing legacy CMS systems

Understanding of trading or affiliate mechanics: attribution (UTM, conversion tracking), commission models, trading operations

Quality-by-Design-Mindset

• We expect Senior engineers to actively reduce QA burden, not generate it. Concretely:

• Code is easy to test - pure functions where possible, dependency injection over globals, clear seams between business logic and infrastructure

• Test plans reviewed with QA before merge, not after bugs ship to production

• Integration and contract tests for every third-party API boundary

• Observable code by default: structured logs, meaningful metrics, traces - so production behavior is debuggable without redeployment

• Comfortable doing post-mortems on your own bugs without defensiveness
  
  Architectural Judjment
  You'll regularly face decisions like "rewrite this legacy module in Symfony, or wrap it?" - and we expect:

• Honest risk assessment based on the actual code, not generic principles

• Clear technical justification documented in ADRs (Architecture Decision Records) or RFCs

• Awareness that incremental change usually beats big rewrites

• Willingness to say "I don't know yet, let me investigate" before committing to a direction
  
  What we offer

• Remote-first with a global, cross-functional team

• Real ownership - you're a core contributor to your services, not a ticket-puncher

• Direct access to a strong engineering bench: tech leads, architects, dedicated DevOps and QA

• Modern tooling budget - AI tools, IDE licenses, learning resources