Available to hire
I’m Tony Merlin, a senior software engineer with two decades of experience building robust backend systems on the JVM, with a strong focus on functional programming. I specialize in designing and delivering resilient, distributed microservices—using Scala and the Typelevel ecosystem (cats, cats-effect, http4s, fs2, doobie), along with event-driven architectures (Kafka, Amazon Kinesis) to help teams build reliable products in complex domains.
I enjoy leading and coaching engineering teams, balancing best practices with pragmatic delivery. My background spans fintech (post-trade, KYC, and matching/payment systems), banking, IoT, transportation, and consumer products, where I’ve helped modernize legacy systems, improve scalability and multitenancy, and build automation around CI/CD and observability so software can ship with confidence.
Experience Level
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Language
English
Advanced
Work Experience
Senior Product Engineer at Yonder
March 1, 2026 - June 30, 2026Automated a previously manual billing/reporting workflow, significantly reducing operational effort. Delivered backend feature enhancements and stability improvements for microservices built with Scala (type-level functional stack), Kafka, and PostgreSQL.
Staff Engineer at GeoSci GmbH
September 1, 2025 - November 1, 2025Led a technical team through a new tech stack and built backend features with Scala and SQL. Integrated an end-to-end production system for data/usage at scale, and advised teams on RAG-based information retrieval for AI use cases. Enhanced infrastructure using AWS/Kubernetes and improved observability and reliability for production services.
Senior Software Engineer II at MOIA (VW Group)
May 1, 2025 - August 22, 2025Refactored a monolithic backend service in Scala 2 to a reactive microservice architecture in Scala 3 utilizing cats and ZIO for safe effects and error handling. Implemented automatic bill-of-materials publishing in payment services to comply with Cyber Resilience Act regulations.
Senior Software Engineer at MOIA (VW Group)
December 1, 2024 - May 31, 2025Refactored a Scala 2 monolith payment backend into event-driven microservices using Scala 3, Cats, ZIO, and Amazon Kinesis, enabling scalability and multitenancy. Automated SBOM publishing and built/maintained GitHub Actions CI/CD pipelines for containerized applications on EKS.
Senior Engineer at MOIA (VW Group)
December 1, 2024 - May 1, 2025Enabled scalability and multitenancy of the payment backend by migrating from a Scala 2 monolith to event-driven microservices with Scala 3, Cats, ZIO, and Kinesis. Automated SBOM publishing and configured messaging infrastructure (Kinesis/SQS) for microservices. Built and maintained GitHub Actions CI/CD pipelines deploying to EKS.
Senior Software Engineer - Contract at Singapore (Remote US)
July 1, 2024 - August 22, 2025Developed RESTful API for third-party insurance verification using Scala 2, Tapir, Akka HTTP, Slick, and PostgreSQL.
Senior Software Engineer at EvidentID
May 1, 2024 - July 1, 2024Built RESTful APIs for end-user identity and compliance services using Akka HTTP (Pekko), Slick, and Postgres, improving performance and correctness of backend workflows.
Senior Product Engineer at Yonder
January 1, 2024 - PresentEliminated a multi-day manual billing process by implementing more automated billing flows. Developed backend microservice movement features using Scala and typelevel libraries (cats, cats-effect, http4s, fs2, doobie) with Kafka and Postgres, improving system reliability and operational efficiency.
AVP Senior Software Engineer at Bank of America Merrill Lynch
December 31, 2023 - August 22, 2025Managed project deliverables end-to-end ensuring 95% stakeholder alignment. Coached and mentored a team of 6 engineers, performed rigorous code reviews. Authored user documentation and conducted workshops resulting in elimination of user errors. Led software enhancements for compliance and post trade processing, reduced defect rate under 2%. Improved system efficiency and resilience using technologies like Kafka, RDF, and functional programming libraries.
Product Engineer at Standard Chartered Bank
December 31, 2019 - August 22, 2025Developed backend wealth management tools using Scala 2 and Typelevel libraries, implementing functional programming for reliability improvements. Designed generational deployment using Kubernetes, Ansible, Jenkins, achieving deployment time and cost reduction over 75%. Enabled asynchronous business verification with 99.999% uptime and coached colleagues on DevOps and test-driven development best practices.
Senior Software Engineer at Bank of America Merrill Lynch
January 1, 2019 - December 31, 2023Delivered enhancements to the bank’s post-trade systems using Scala with Typelevel (cats, cats-effect, http4s, fs2) and Python, along with Kafka and RDF-based data modeling. Added BlackRock compatibility to post-trade matching and mentored teams to drive continuous improvement.
VP Senior Software Engineer at Bank of America
January 1, 2019 - January 1, 2023Built and delivered improvements to the bank’s KYC system using Scala with typelevel libraries (cats, cats-effect, http4s, fs2) plus Python and Kafka, including RDF-based data modelling. Added BlackRock compatibility to an existing data pipeline and mentored teams through technical reviews and process improvements.
Consultant Software Architect at Standard Chartered Bank
January 1, 2018 - December 31, 2019Built backend wealth management services with a focus on reliability. Designed and improved release processes to reduce release time from 1–2 days to minutes using a rainbow deployment approach, with stakeholder-friendly test URLs and robust rollback. Helped ensure 99.999% uptime via asynchronous verification and rollback strategies.
Senior Software Engineer at Standard Chartered
January 1, 2018 - January 1, 2019Built backend wealth management tools with Scala 2 and typelevel libraries (cats, cats-effect, http4s), improving reliability and performance. Designed and built a Kubernetes release system using Jenkins CI/CD and automated configuration reduction, cutting deployment effort and improving rollback safety.
Consultant Software Developer at ThoughtWorks
December 31, 2017 - August 22, 2025Enhanced software within an agile scrum team using pair programming for knowledge sharing and team efficiency. Developed NLP search enhancements with Python 3, SpaCy, and Django, ensuring 100% customer satisfaction and on-time delivery.
Consultant Software Architect at ThoughtWorks
January 1, 2017 - January 1, 2018Delivered a natural language processing (NLP) search solution, applying Agile practices and partnering with stakeholders to deliver robust software outcomes.
Consultant Software Architect at Coca-Cola
December 31, 2016 - August 22, 2025Re-architected consumer-facing IoT platform from PoC to global production, reducing outages drastically. Improved platform scalability and resiliency, reducing support costs over 90%. Redesign included Akka actor hierarchy, caching with Redis, migrations to PostgreSQL, and agile methodology introduction, cutting time-to-market by 75%. Worked with Scala 2, Play Framework, Akka, Redis, PostgreSQL, and MySQL.
Software Developer Team Lead at Berkshire Hathaway Energy
December 31, 2015 - August 22, 2025Led six-person team to develop IoT solutions for energy management on US Military bases. Defined development process, git branching strategy, and built SBT plugin to streamline deployments by 90%. Developed RESTful services, operational tools, and reports using Scala 2, Play Framework, Apache Cassandra, and Apache Spark.
Consultant Software Architect at Coca-Cola North America
January 1, 2015 - December 31, 2016Scaled an IoT consumer platform from MVP to a distributed system capable of global scale. Implemented backend/storage improvements using PostgreSQL with Redis caching to reduce support costs by 90%.
Consultant Software Architect at Coca-Cola
January 1, 2015 - January 1, 2016Scaled an IoT consumption system with reliability improvements and reduced persistence costs by using SQL with Redis caching. Contributed to global-scale production support and infrastructure improvements.
Senior Software Engineer at Various Roles in Mannheim and Atlanta, USA
December 31, 2014 - August 22, 2025Modernized legacy software stacks with agile methodologies, improving maintainability and developer productivity. Worked on health and wellness social network (sharecare.com) using Java 7, JSP, Spring MVC, and MongoDB. Scaled global payment infrastructure throughput with Java and JMeter, saving costs with open source solutions. Led software quality team and contributed as technical artist at Turbo Squid.
Software Team Lead at Berkshire Hathaway Energy
January 1, 2014 - December 31, 2015Led a team of 6 building infrastructure and services. Automated deployment pipelines using Git, SBT, Jenkins, and Chef, reducing build and deployment times and improving consistency.
Team Lead at Berkshire Hathaway Energy
January 1, 2014 - January 1, 2015Led a team of six engineers building IoT platform components and automated deployment using Git, SBT, Jenkins, and Chef, reducing deployment overhead. Managed team delivery for operational stability and predictable releases.
Lead Performance Test Engineer
January 1, 2010 - PresentLed a team of three engineers creating performance testing infrastructure and testing framework components for software quality.
Senior Software Engineer
January 1, 2006 - January 1, 2014Built backend services for a health and wellness platform using MVC and MongoDB, supporting millions of users.
Education
Certification Specialization at Coursera c/o École Polytechnique Fédérale de Lausanne
January 11, 2030 - August 22, 2025Certification in Requirements Analysis, Leadership and Ethics at Global Payments, USA
January 11, 2030 - August 22, 2025Design and Technical Training for Film and Visual Effects at Savannah College of Art and Design
January 11, 2030 - August 22, 2025Functional Programming in Scala Specialization at École Polytechnique Fédérale
January 11, 2030 - September 14, 2026Cybersecurity at Ce
January 11, 2030 - September 14, 2026Education Analysis, Leadership at I'A
January 11, 2030 - September 14, 2026Design & Technical Training (Film and Visual Effects) at Savannah College of Art and Design
January 11, 2030 - September 14, 2026Functional Programming in Scala Specialization (Coursera/École Polytechnique Fédérale de Lausanne) at École Polytechnique Fédérale de Lausanne (Coursera)
January 11, 2030 - September 23, 2026Certifications in Requirements Analysis, Leadership & Ethics at Global Payments, USA
January 11, 2030 - September 23, 2026Design for Film and Visual Effects at Savannah College
January 11, 2030 - September 23, 2026Qualifications
Functional Programming in Scala Specialization
January 11, 2030 - August 22, 2025Certification in Requirements Analysis, Leadership and Ethics
January 11, 2030 - August 22, 2025Design and Technical Training for Film and Visual Effects
January 11, 2030 - August 22, 2025Functional Programming in Scala Specialization
January 11, 2030 - September 14, 2026N/A
January 11, 2030 - September 14, 2026Certified in Cybersecurity
January 11, 2030 - September 23, 2026Certified in Cybersecurity
January 11, 2030 - September 23, 2026Functional Programming in Scala Specialization (EPFL via Coursera)
January 11, 2030 - September 23, 2026Requirements Analysis (Global Payments)
January 11, 2030 - September 23, 2026Leadership & Ethics (Global Payments)
January 11, 2030 - September 23, 2026Design for Film and Visual Effects
January 11, 2030 - September 23, 2026Industry Experience
Financial Services, Transportation & Logistics, Software & Internet, Energy & Utilities, Media & Entertainment, Government, Computers & Electronics, Consumer Goods, Other
Experience Level
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Hire a Developer
We have the best developer experts on Twine. Hire a developer in London today.