Principal Software Engineer, Fintech

T-Mobile•Frisco, TX

13d

About The Position

At T-Mobile, we invest in YOU! Our Total Rewards Package ensures that employees get the same big love we give our customers. All team members receive a competitive base salary and compensation package - this is Total Rewards. Employees enjoy multiple wealth-building opportunities through our annual stock grant, employee stock purchase plan, 401(k), and access to free, year-round money coaches. That’s how we’re UNSTOPPABLE for our employees! Are you ready to shape the future of financial technology at the Un-carrier? We’re building the next generation of payments, money movement, and digital financial services that serve millions of customers every day. As a Principal Software Engineer in Fintech, you’ll be a hands-on technical leader driving architecture, scalability, and innovation across real-time payment systems, data pipelines, and compliance-ready financial platforms. You’ll mentor engineers, influence architecture across multiple domains, and ensure our systems are resilient, observable, and secure. You’ll partner with Product, Compliance, and Risk teams to deliver financial experiences that are fast, transparent, and trustworthy — all while embodying the bold, innovative spirit of the Un-carrier.

Requirements

Java Microservices: Java 11+, Spring Boot, RESTful APIs, OpenAPI, backward-compatible versioning.
Eventing & Schemas: Kafka or AWS EventBridge; schema registry with compatibility rules.
Data & Caching: PostgreSQL, DynamoDB, Redis, S3; clear transaction boundaries; performance-minded SQL/NoSQL design.
Batch & Scheduling: Spring Batch / AWS Batch / Quartz; resilient, retryable, restartable jobs.
ETL / ELT: AWS Glue (Jobs, Workflows, Crawlers, Data Catalog); Snowflake (Snowpipe, Streams & Tasks, RBAC, masking, performance tuning).
Kubernetes Delivery: Docker/Helm on EKS; HPA, pod security, Terraform automation.
CI/CD & Quality: Maven, SonarQube; unit/integration/performance testing; SAST/DAST; dependency governance; blue/green and canary deployment.
Observability: OpenTelemetry traces/metrics/logs; Splunk dashboards and alerts; end-to-end correlation across services.
Production Excellence: On-call leadership; JVM debugging (jstack, jmap); RCA facilitation and preventive automation.
Cybersecurity (hands-on): OAuth2/OIDC, JWT hardening, mTLS; IAM least-privilege; secrets rotation (KMS/Secrets Manager); OWASP Top 10/CWE mitigations; Kubernetes hardening.
Engineering Practices: Rigorous code and design reviews, pair/mob programming, API governance, rollout and rollback strategies.
Fintech Domain Experience (Required): Strong experience with Payments and Money Movement (e.g., ledgers, settlements, reconciliation, disputes).
Exposure to Risk & Compliance workflows such as KYC/KYB/AML orchestration, sanctions screening, or fraud prevention.
Understanding of financial data handling and auditability (retention, masking, observability).
Bachelor’s degree in Computer Science, Software Engineering, or related field (required).
7-10+ years of software engineering experience with increasing scope and technical leadership.
Demonstrated experience leading architecture or platform modernization in regulated or financial systems.

Nice To Haves

Open Banking: Financial-grade API (FAPI), Financial Data Exchange (FDX), account opening and management.
Regulatory Reporting & Data Residency: Data retention and auditability patterns.
Ecosystem Familiarity: Processors, identity and fraud vendors, and partner integration models.

Responsibilities

Lead the architecture and implementation of scalable, event-driven financial systems supporting payments, settlements, and reconciliations.
Drive adoption of modern Java microservice patterns using Spring Boot, RESTful APIs, and contract-first design (OpenAPI).
Champion observability and production excellence — ensuring deep traceability, resilience, and performance across distributed systems.
Mentor engineers across teams, establish best practices in design reviews, testing, and secure development.
Partner with cross-functional leaders in Product, Compliance, and Security to align technology with business and regulatory needs.
Serve as an expert resource in Fintech system design, security, and cloud-native delivery.
Define and evolve the Fintech engineering roadmap — balancing innovation with compliance, scalability, and reliability.
Evaluate emerging financial technologies and guide adoption of event streaming, data analytics, and automation frameworks.
Quantify technical decisions with clear ROI, cost, and risk trade-offs; align architecture with long-term platform objectives.
Contribute to engineering standards, API governance, and rollout/rollback strategies across the organization.
Design and optimize batch and streaming data pipelines for settlements, reporting, and reconciliation using AWS Glue, Snowflake, and Kafka/EventBridge.
Automate infrastructure delivery via Kubernetes (EKS), Docker, Helm, Terraform, and enforce strong pod and IAM security policies.
Implement robust CI/CD and quality frameworks with Maven, SonarQube, and progressive delivery (blue/green, canary).
Lead incident response and RCA processes for complex production issues; codify learnings into reusable automations and runbooks.
Contribute to intellectual property creation through innovative financial system design.
Produce high-quality documentation of system architecture, APIs, and operational processes.
Communicate complex technical concepts clearly to both engineering and executive stakeholders.
Foster a learning culture through brown-bags, technical workshops, and mentoring.