Principal Engineer & Technical Lead — .NET & Azure

About Aperia Solutions

Aperia Solutions is a leading payments SaaS company headquartered in Dallas, Texas. We build risk management, residuals accounting, compliance, and analytics platforms used by merchant banks, ISOs, payment processors, and other participants in the credit card payments ecosystem. Operating under PCI DSS 4.0 compliance across dual on-premises datacenters (Allen, TX and Chicago, IL) plus Azure cloud, we process high-volume payment data for some of the industry’s largest players.

We’re in the middle of a significant platform modernization program: a next-generation risk analysis and scoring platform on Microsoft Fabric, an AI-powered ingestion platform, new AI-native applications, and ongoing evolution of the products our clients rely on every day. The teams executing this work are deliberately small and senior, with executive-level support and minimal bureaucracy. Every senior hire is a founding contributor to the architecture and the code.

Role summary

We are hiring a Principal Engineer and Technical Lead: a builder first, with deep architecture and enterprise design pattern experience behind every line of code. This person is the SVP of Technology's chief lieutenant on technical execution. You will take on the heaviest technical lifting, prove risky ideas with working prototypes, turn approved architecture into production systems, and hold distributed engineering teams to a high technical bar.

This is a hands-on role, not an architecture-only or slideware role. Target architecture is set with technology leadership; you own making it real, from implementation design, code and IaC through the hard production problems, and you push back with evidence when a design won't hold up in implementation.

The platform is a regulated, multi-tenant payments SaaS built on Azure, Microsoft Fabric, AKS, C#/.NET and Python. You will report directly to the SVP of Technology and act as the senior hands-on technical authority across platform, data and AI initiatives.

Title options: Principal Engineer, Lead Software Engineer / Technical Lead – Cloud Platforms, or Staff Engineer – Azure.

What you'll do

Hands-on engineering, POCs and heavy lifting (≈50%)

• Build working prototypes and POCs for advanced concepts (LLM/RAG services, event-driven pipelines, multi-tenant patterns, new Azure services) to retire technical risk before teams commit.
• Own the hardest technical slices end to end: write and ship production-quality C#/.NET and Python, debug production issues, and unblock teams by doing the work rather than delegating it.
• Implement enterprise design patterns in real code: event-driven and messaging (outbox, saga, idempotent consumers, retries and dead-lettering), CQRS, resilience (circuit breaker, bulkhead, backpressure), caching and multi-tenant isolation.
• Author and review IaC (Terraform/Bicep), Helm charts and CI/CD pipelines; build the golden-path templates teams adopt.
• Benchmark and load test candidate designs; bring numbers, not opinions, to technical decisions.
• Take on heavy-lift tasks directly from the SVP: technical spikes, hands-on vendor evaluations, migration tooling, and performance and cost investigations.

Design and implementation patterns (≈25%)

• Turn target-state architectures into implementation designs: service boundaries, contracts, data models and deployment topology across AKS, Container Apps, Functions, APIM, Service Bus/Event Hubs, Cosmos DB and Azure SQL.
• Build and harden integration paths into Microsoft Fabric (OneLake, Lakehouse/Warehouse, mirroring, Real-Time Intelligence), knowing where the sharp edges are from having hit them.
• Write ADRs and design docs for the decisions made during implementation, and contribute to architecture reviews and threat models with implementation-level detail.
• Implement regulated-workload controls in code and IaC: network isolation, private endpoints, identity (Entra ID, managed identity, workload identity), secrets, encryption and audit.
• Bring run-cost to every build: estimate before, measure after, and flag designs that won't scale economically.

Technical leadership with delivery teams (≈25%)

• Act as the SVP's chief lieutenant on technical execution: carry decisions into teams, keep builds aligned with approved designs, and stand in on technical matters when the SVP is unavailable.
• Run design reviews, code reviews and technical checkpoints with onshore and offshore teams across multiple time zones.
• Track technical status and surface risk early: integration gaps, drift from approved designs, quality and security debt.
• Mentor senior engineers and tech leads; raise the bar on implementation quality, testing and observability.
• Translate implementation status and risk into concise options for technology leadership, and work directly with security, product and vendors.

Technical stack

Candidates should be expert in the core column and fluent in most of the adjacent column.

Area	Core (expert)	Adjacent (fluent)
Cloud	Azure: AKS, Container Apps, APIM, Functions, Service Bus, Event Hubs, Key Vault, Front Door	Azure Policy, Landing Zones, AWS/EKS equivalents
Data	Microsoft Fabric, OneLake, Cosmos DB, Azure SQL	Databricks, Synapse, ClickHouse, Kafka
Languages	C# / .NET 8+, Python	TypeScript, SQL/KQL, Go
Design patterns	Event-driven/messaging (outbox, saga, idempotency), CQRS, resilience patterns, multi-tenant isolation	DDD, hexagonal/clean architecture, API versioning, enterprise integration patterns
Containers	Docker, Kubernetes, Helm	Dapr, KEDA, service mesh, GitOps (Flux/Argo)
IaC and delivery	Terraform, Azure DevOps or GitHub Actions	Bicep, policy-as-code, container image signing/scanning
AI	Azure OpenAI / AI Foundry, RAG patterns	Semantic Kernel, LangChain, vector search, evaluation tooling
Observability	Azure Monitor, App Insights, OpenTelemetry	Prometheus, Grafana
Security	Entra ID, managed/workload identity, private networking	Defender for Cloud, PCI DSS controls

Required qualifications

• 12+ years in software engineering, including 5+ years as a lead or principal engineer shipping production cloud systems.
• 4+ years building and operating containerized workloads on Kubernetes in production, preferably AKS.
• Deep, current hands-on Azure experience: you have personally built, deployed and debugged the services you work with.
• Code you can show: substantial, active C#/.NET and Python work in the last 12 months, not just reviews. You are still one of the strongest individual contributors on any team you join.
• Deep, applied command of enterprise design patterns (messaging, resilience, integration, multi-tenancy); you can explain their failure modes because you have hit them in production.
• Track record of taking a novel concept from whiteboard to working POC in weeks, then building or leading the first production slice.
• Working architecture depth across operational and analytical data stores, including event-driven and streaming implementations.
• Fluency with IaC and CI/CD; you write the Terraform and the pipeline, not just the diagram.
• Security-first implementation in a regulated environment (PCI DSS, SOC 2, or financial services equivalent).
• Proven ability to lead distributed and offshore teams through design and code reviews without direct authority.
• Clear written communication: ADRs, design docs and status summaries that stand on their own.

Preferred qualifications

• Payments, card processing, risk/fraud, or merchant services domain experience.
• Production Microsoft Fabric work, including mirroring from Cosmos DB or SQL and Fabric capacity sizing.
• Shipped LLM-backed features: RAG, agent/tool patterns, content safety, evaluation and red-teaming.
• Multi-tenant SaaS design: tenant isolation, noisy-neighbor controls, per-tenant cost attribution.
• Azure certifications such as Azure Developer (AZ-204), DevOps Engineer Expert (AZ-400), CKAD/CKA, or Fabric Analytics Engineer (DP-600). Nice to have, never a substitute for demonstrated work.
• Open-source contributions, technical writing or conference talks.

Eligibility Requirements

Must be willing to submit to a background investigation and drug test as part of the selection process.

Job Type

Full-time

Schedule

Hybrid: Monday to Friday

Work Location

Dallas, TX

Benefits

• Health insurance
• Health savings account
• Dental insurance
• Vision insurance
• 401(k) matching
• Life insurance
• Paid time off
• Parental leave
• Disability insurance
• Childcare assistance
• Education reimbursement
• Fitness membership
• Volunteer time off