← All roles

Principal Engineer

Aleph Holding· Staff – Research & Development
Apply on company site
Hybrid (Madrid)Full time - permanentPosted 2mo ago

About the role

Senior individual-contributor role overseeing integration and data architecture for ingesting from and pushing to external ad/social platforms, maintaining coherence of a polyglot tech stack, and driving strategic technical decisions through influence and code.

Responsibilities

  • The integration architecture for ingesting from and pushing to external ad/social platforms — versioning, rate limits, backfills, idempotency, webhooks, and graceful degradation when a partner API changes underneath us.
  • The data architecture for information flowing between platforms and internal systems: pipelines, reconciliation, contracts between services, and the path from operational data to reporting.
  • A pragmatic strategy for modernizing the legacy estate — strangler-fig migrations, clear service boundaries, and sound judgement about which language and pattern fit each problem — carried far enough into code that teams can follow the pattern.
  • The engineering bar for integration and data work: the reference implementations, patterns, and standards the org builds against, ratified through the technical committee.
  • Set the technical direction for new products and major changes, and stay the technical decision-maker through build and post-launch — with the authority to course-correct when implementation drifts, and the habit of being in the codebase to catch the drift early.
  • Build the hard parts yourself. Write production code on the riskiest, highest-leverage paths; prototype the uncertain approach to turn an argument into evidence; build the reference implementation others extend.
  • Turn intangible trade-offs — partner API risk, team capability, long-term scalability, cost of change — into clear, written decisions (ADRs) that leadership and the technical committee can sign off on.
  • Define service and data contracts, integration patterns, and resilience strategies that survive third-party API deprecations and outages.
  • Go deep when it breaks: lead diagnosis on the gnarliest production incidents and performance regressions, and land the fix and the systemic follow-up.
  • Identify the infrastructure (compute, data, messaging, observability) needed to meet current and near-future goals.
  • Raise the bar through others: mentor engineers and tech leads, set the standard in code review, and drive cross-functional decisions across engineering, product, security, and operations — through influence, not line management.
  • Evaluate third-party and vendor solutions against our integration and data requirements.
  • Monitor systems against performance and business benchmarks and escalate with concrete recommendations.

Qualifications

  • Substantial experience as a staff/principal engineer (or equivalent) on integration-heavy, data-heavy systems — ideally where you didn't control the external APIs.
  • Still hands-on. You lead by building, and you're demonstrably strong in production code, not only in design.
  • Depth in at least one of PHP, Go, or Python, and comfort across a polyglot estate (TS/JS on the front).
  • A track record of modernising legacy systems incrementally without halting delivery.
  • Fluency in integration and data patterns: idempotency, eventual consistency, rate limiting, queuing, backfills/reconciliation, API versioning.
  • A history of driving technical decisions through influence rather than authority — getting senior leadership and peer engineers to commit to a direction, and backing it with working code.

Skills

Required:Integration architectureData architectureLegacy modernizationProgramming languages
Last updated Oct 21, 2026. Interested? Apply on the company site.

About Aleph Holding

Aleph is making digital advertising accessible around the world

A leading global enabler of digital advertising in emerging countries

digital advertisingemerging marketstechnologypaymentssolutions
Company profileWebsite

More open roles at Aleph Holding