# Adam Yen > Software Engineer | Backend & Distributed Systems Location: Sunnyvale, California, United States Profile: https://flows.cv/adamyen Backend software engineer with 15+ years of experience owning and operating large-scale distributed systems in fintech, telecom, and enterprise environments. Proven record of leading complex migrations and rollouts involving irreversible changes, third-party dependencies, and cross-team decision making. Green card holder, open-source author. Strong hands-on background in Java, JavaScript, C#, SQL/NoSQL, and event-driven architectures. Drives efficiency and standards across the development lifecycle (CI/CD, DevOps, reproducibility), production operations (dashboards, alerting, incident response and follow-ups), and risk mitigation (feature flags, phased rollouts, rollback plans). Frames ambiguous problems, makes durable technical decisions, and owns outcomes end-to-end ## Work Experience ### Founding Engineer @ Core16 Jan 2024 – Present | Mountain View, California, United States ### Staff Software Engineer @ BILL Jan 2023 – Jan 2024 | San Jose, California, United States • Acted as technical owner for international vendor setup and cross-border payments, including country-specific bank account validation, foreign currency exchange, money disbursement, regulatory-related changes, and integrations with external banking APIs, covering 130+ countries in 100+ currencies, sending over $1 billion in annual payment volume. • Led cross-org decision and delivery of new local-currency payout method across 23 countries, prioritizing reversible UX and gradual rollout over aggressive timelines, while minimizing blast radius of failing countries and turning recoveries into low-severity incidents. Reduced payment delivery time from 6 to 2 days, cut vendor support tickets, and accelerated volume growth by $7M in the first 4 months. • Identified 80k misclassified international vendors in the accounting software Sync pipeline. Framed two possible migration paths with explicit risk and ownership trade-offs. Recommended a lower-risk Sync-led path, and after leadership chose a higher-risk path, implemented and ran irreversible production migration with dry runs and rollout caps (+34k net vendors, +7k/yr projected). • Established data visibility for engineering and product leadership by defining new metrics for vendors, payments, and currency exchange (such as bank search failure rates, invoices marked as paid externally, payout method volume comparison). Built operational dashboards in Datadog, used in weekly leadership reviews to guide country prioritization, detect financial trends early, and inform data-driven marketing decisions ### Lead Software Engineer @ Verizon Jan 2020 – Jan 2022 | San Diego, California, United States • Owned cross-department integration of new company-wide authorization API across 3 engineering teams, setting the rollout strategy and execution plan. Designed and implemented a Spring Boot application as an API facade to absorb external complexity and ongoing changes, cache authorization data, and bridge to existing service bus infrastructure. Provided early, actionable feedback that improved API consistency and reliability prior to broad adoption. • Planned and executed a time-sensitive migration of 17 years of source code history from SVN to Git, splitting monorepos and unifying fragmented legacy history. Developed a custom high-speed approach that reduced migration execution from days to under 1 hour per repository, unblocking modern tooling adoption across the department without interrupting active development. • Promoted and led adoption of DevOps and observability standards across multiple applications, making the delivery lifecycle visible, enabling earlier detection of production issues, and significantly reducing incident investigation time. Introduced Jenkins CI/CD pipelines, standardized Git workflows, private package management, and code review and test-coverage gates. • Resolved several long-standing, high-impact production issues, including load balancer sticky-session glitches, inconsistent wireless plan data, and intermittent failures when activating 5k+ devices concurrently. Focused on eliminating root causes and failure modes rather than workarounds, resulting in zero recurrence. ### Lead Software Engineer @ EPAM Systems Jan 2019 – Jan 2022 | San Diego, California, United States Client engagements: Verizon (2020–2022), SLB (2019–2020). ### Lead Software Engineer @ SLB Jan 2019 – Jan 2020 | Houston, Texas, United States • Acted as technical lead for a new predictive maintenance platform processing real-time equipment telemetry, defining scope with stakeholders and translating field constraints into a delivery plan. Designed system architecture and integration APIs connecting 3 external systems and industrial equipment. • Built and scaled a microservices-based backend, delivering multiple REST services and ETL pipelines (InfluxDB) on top of a customer framework. Set up containerized deployments and CI/CD across a hybrid cloud (Azure pipelines, GCP infrastructure). • Coordinated execution across 3 globally distributed teams (US and India), aligning interfaces, milestones, and ownership. Shipped functionality that prevented critical equipment failures, avoiding costly repairs with estimated savings of $600K+ annually. ### Senior Software Engineer @ Tickeron Jan 2018 – Jan 2019 | Astana, Kazakhstan • Architected and led development of a new homepage module with a team of 2 engineers, increasing paid-subscription conversion by 10%. • Implemented OAuth2 authentication with Google, contributing to 8k new users within 3 months. ### Senior Software Engineer @ Wolters Kluwer Jan 2016 – Jan 2018 | Astana, Kazakhstan • Led a team of 3 people in CRM migration due to business reorg, meeting a 2-month deadline. • Raised application’s Google page rank up to the first page by implementing SEO audit recommendations. ### Software Engineer @ NCOC Jan 2014 – Jan 2016 | Astana, Kazakhstan • Built new features and interactive data visualizations as a full-stack developer using Angular and .NET. • Performed performance tuning of stored procedures reducing click-to-response latency from 30 to 1 second. ### Software Engineer @ Ministry of Finance of the Republic of Kazakhstan Jan 2009 – Jan 2014 | Astana, Kazakhstan • Developed 20+ REST API and SOAP web services for e-government. Created a library to apply/verify digital signatures. • Integrated 4 payment gateways into a public web application, increasing its payment volume by multiple times. ### Software Engineer Intern @ NAT Kazakhstan JSC Jan 2009 – Jan 2009 | Astana, Kazakhstan • City electric grid monitoring application. • Fixed bugs, made SQL queries, designed user interface. ### Software Engineer Intern @ Smart Ex Jan 2007 – Jan 2008 | Astana, Kazakhstan • Developed Windows desktop application in a team of 3 people to track college warehouse supplies. ## Education ### Master in Mathematics and Computer Science L.N.Gumilyov Eurasian National University ### Bachelor in Mathematics and Computer Science L.N.Gumilyov Eurasian National University ### Graduate in Electrical and Electronics Engineering Electronics Club ## Contact & Social - LinkedIn: https://linkedin.com/in/adam-yen --- Source: https://flows.cv/adamyen JSON Resume: https://flows.cv/adamyen/resume.json Last updated: 2026-04-05