Product leader and research professional with more than two decades across software, UX, product, analytics, and regulated technology. I began in hands-on usability research at Microsoft, joined Adobe's Global Market Research team for Acrobat and Reader, moved into product ownership at ACD Systems, and led requirements work for a certified EMS product at Medusa.Today I build and ship local-first browser software at Red5Sorcery, using AI extensively across requirements, implementation support, adversarial QA, documentation, and release acceptance.
The ownership level changed across my career, so I make that distinction explicit. This is the product list at a glance; the detailed history below explains exactly what I contributed to each.
Began at Microsoft in the Business Tools Division UX (BTDUX), conducting usability research and design evaluation for the Calendar, Timeline, and Organization Chart feature areas supporting the shipped release.
Later moved to Microsoft's Office Design Group, conducting usability testing for Search, My Sites, List Management, and the IT administration/deployment console before leaving for Adobe in 2005.
Global Market Research contribution using surveys and user studies to help the Acrobat and Reader teams understand customers and refine product messaging, market positioning, and language for the shipped v8 releases. Reader 8 also became part of Adobe’s free-software distribution channel for the Google Toolbar, connecting an enormous consumer footprint to a commercially important partnership I supported through separate prototyping and usability research.
Contributed early research for the next Acrobat generation before leaving Adobe in 2008; this is research contribution, not release ownership.
Challenged a planned Microsoft Ribbon-style direction and won support for a modal, workflow-based redesign closer to Lightroom—using paper prototypes, mockups, and company-wide presentations to make the case.
0→1 product definition through launch, including EXIF/IPTC metadata search and organization, Batch Develop processing for photographers’ image transformations, and a public beta of more than 10,000 users.
Worked on the shipped v2 release and launch, continuing the Mac product line after v1 with expanded photo-management and processing capabilities.
Product and requirements leadership through release and successful NEMSIS v3.4.0 certification.
Offline browser privacy software conceived and shipped with Rust and WebAssembly.
Local-first browser software for private, explainable data analysis; I own end-to-end product definition and acceptance.
Before product ownership became the centre of my work, I spent years in hands-on UX research at Microsoft and then Global Market Research at Adobe, backed by formal experimental research in Human Factors. The toolkit ranged from controlled interface studies and prototyping to field research, messaging studies, and large-sample market research, and I also taught research techniques directly to development teams.
Traditional moderated usability studies, including think-aloud / talk-aloud protocols while participants completed realistic tasks.
Controlled comparative interface testing and benchmarking used to evaluate competing designs and interaction approaches.
Structured cognitive walkthroughs used to evaluate proposed workflows, features, interactions, and specifications before implementation.
Collaborative walkthroughs that brought multiple perspectives into the evaluation of interface concepts and task flows.
Site visits, contextual inquiry, and ethnographic research focused on understanding real work practices in the environments where they occurred.
Moderated group research used to explore user needs, reactions, expectations, terminology, and emerging product questions.
Quantitative survey research conducted with large-sample market research vendors, including Harris Interactive, alongside specialized user-research consultants.
At ACD Systems, designed and conducted Net Promoter Score (NPS) survey research with actual ACDSee Windows users to understand why they would — or would not — recommend the product, turning recommendation drivers and detractors into product evidence.
Used low-fidelity paper prototypes and higher-fidelity interactive prototypes to make design alternatives tangible before implementation. During my Adobe years, I built an interactive Macromedia Director simulation of the proposed Adobe–Google Toolbar distribution experience. The work turned a not-yet-built installation flow into something the partnership team could test under tight deadlines, giving negotiators evidence about how the experience would actually feel to Adobe users. Adobe publicly described the multi-year Google agreement as expected to represent significant revenue over a period of years; Reader 8 later became one of the free Adobe download experiences through which the Google Toolbar was offered.
My academic research included controlled experimental interface testing published in Human Factors: “Designing an Interface to Optimize Reading with Small Display Windows” ↗.
At Microsoft, delivered workshops to the SharePoint development team on using cognitive walkthroughs while designing features and writing specifications.
I started by observing how people used complex software and turning that evidence into design guidance. Over time, the responsibility moved closer to the product itself: research, then feature and workflow decisions, then release ownership, regulated certification, and now founder-led delivery.
Microsoft and Adobe taught me to start with observed behaviour, controlled research, and the difference between what users say and what they actually do.
At ACD Systems and Medusa, I moved into prioritization, workflow design, requirements, validation, launch readiness, and externally governed product delivery.
At Red5Sorcery I define the product, use AI deeply in implementation and QA workflows, accept or refuse releases, publish the documentation, and ship.
The progression is visible above. The expandable record below separates research contribution, feature/workflow contribution, 0→1 ownership, regulated delivery, and founder-level accountability.
These are products where my contribution was research, design guidance, workflow modernization, selected features, or launch support—not always end-to-end ownership. Visio 2003, Acrobat 8 / Reader 8, ACDSee Pro 3, and ACDSee Pro 2 for Mac were shipped releases I directly supported; SharePoint is included as product research, and Acrobat 9 as early pre-release research, rather than releases I claim to have owned or shipped.
Began at Microsoft in the Business Tools Division UX (BTDUX), conducting usability research and design evaluation for Visio 2003 feature areas including Calendar, Timeline, and Organization Chart. Findings informed interaction and design decisions in the shipped product.
Worked on Adobe's Global Market Research team, synthesizing survey and user-study evidence to help Acrobat and Reader teams understand customers and refine product messaging and market positioning for the shipped v8 releases. Reader 8 was also distributed free and later offered the Google Toolbar through its download/install experience, extending Adobe’s broader Google distribution partnership.
Contributed early research for the next Acrobat generation before leaving Adobe in 2008. I describe this as upstream research contribution rather than ownership of the eventual release.
Early in my ACD Systems role, engineering was preparing to follow Microsoft’s Ribbon UI paradigm. I challenged that direction and proposed a modal, workflow-based interface closer to Lightroom. I created paper prototypes and mockups, presented the case to the executive team and the wider company, and the direction was adopted. I also contributed selected features, including Quick Search for metadata-rich photo libraries.
Moved from the Business Tools Division UX (BTDUX) into Microsoft's Office Design Group, where I tested SharePoint Portal Server Search, My Sites, List Management, and the IT administration/deployment console. This extended my research from end-user collaboration experiences into deployment and administration workflows. I left for Adobe in 2005, so I describe this as product research rather than a release I owned.
This is where my role moved from influencing decisions to owning product definition, requirements, release readiness, certification, or founder-level acceptance.
Led product definition through launch, including workflow design, prioritization, release readiness, EXIF/IPTC metadata search and organization, and Batch Develop processing for applying photographers’ transformations across groups of images. Helped lead a public beta of more than 10,000 users.
Worked on the second major Mac release and its launch, continuing the product line I had helped establish with v1. I describe this as a shipped product contribution rather than claiming sole ownership of the release.
Led product and business requirements analysis through release and successful NEMSIS v3.4.0 certification, translating EMS field workflows and the national data standard into specifications, validation rules, and implementation decisions.
Conceived and shipped an offline browser privacy application built with Rust and WebAssembly, owning the path from concept through validation, release, documentation, and publication.
Own end-to-end product definition, workflow design, requirements, acceptance criteria, implementation decisions, QA evidence, documentation, and iterative release acceptance for a local-first data-analysis workbench.
Red5Sorcery Books & Media publishes technical books, source code, and software focused on privacy, data analysis, and practical technology, alongside separate games and entertainment projects. It is also where the full arc of my career comes together: research, product definition, implementation evidence, QA, documentation, and release accountability.
A local-first browser application for private, explainable data analysis. I own product definition, workflow design, requirements, acceptance criteria, implementation decisions, QA evidence, documentation, and iterative release acceptance.
Visit Red5SorceryDataSculptor.com ↗Offline browser privacy software built with Rust and WebAssembly. Conceived and shipped from product concept through implementation, validation, release, documentation, and publication.
Visit CloakYourSecrets.com ↗Publishing technical work that makes product decisions, source code, privacy ideas, and data-analysis practices inspectable rather than mysterious.
Explore selected work ↓I work extensively with ChatGPT, Claude, and Gemini inside a structured, human-led product-development process. AI contributes across the lifecycle; final product decisions and acceptance remain mine.
AI is embedded in the work — requirements, implementation support, critique, QA, documentation, evaluation, and verification.
The value is not simply using multiple models. It is assigning clear responsibilities, preserving decision evidence, reconciling competing input, and keeping one accountable human responsible for the product.
Across the roles, the pattern is consistent: study the workflow, make the ambiguity explicit, turn evidence into decisions, and leave a product or analysis that people can actually use and explain.
I have 18 LinkedIn recommendations from 2007–2013, written by managers, peers, researchers, engineers, QA specialists, designers, and business partners. I selected six excerpts that reinforce different parts of my professional story: research depth, scientific product judgment, user-centred delivery, cross-functional execution, and how I work with people.
“Tarjin approaches product management decisions from a scientific perspective, which is rooted on his background in usability.”
“Tarjin is a versatile and talented researcher who has both delivered qualitative user research as well as quantitative market research projects while working in Global Market Research.”
“Tarjin is an excellent Product Manager, and it's a pleasure to work with Tarjin at ACD Systems.”
“I worked closely with Tarjin on ACDSee Pro (Mac) project for more than 4 years. He was very detail-oriented and enthusiastic about gathering user feedback, providing a good user experience…”
“I worked with Tarjin under tight deadlines on the high profile Adobe-Google Toolbar distribution deal. Tarjin was quick to understand my goals, develop prototypes and testing scripts for end user testing…”
“It's rare to find someone so down-to-earth, yet so thorough in his work… this man brings a crystal sharp mind that's ready to roll.”
Selected from 18. These are short excerpts; LinkedIn retains the original recommendations, dates, relationship context, and complete wording.
View all 18 recommendations on LinkedIn ↗Documents the product-development practices, architecture decisions, and human-AI collaboration behind Red5Sorcery Data Sculptor.
Published by Red5Sorcery Books & Media.
Daily series documenting product decisions, technical trade-offs, QA, communication, and the ongoing development of Data Sculptor.
Rahman, T., & Muter, P. Human Factors, 41(1), 106–117. Controlled experimental research on interface design and reading performance—part of the formal research foundation I later brought into commercial product work.
Large, A., Beheshti, J., & Rahman, T. 38(3), 427–443.
Large, A., Beheshti, J., & Rahman, T. 53(2), 79–94.
McGill University
University of Toronto · HCI / applied cognitive science; formal experimental design and controlled interface testing
Dalhousie University
Scrum.org · 2017
Product ownership, strategy, roadmaps, backlog prioritization, business and workflow analysis, requirements, user stories, acceptance criteria, process improvement, interaction and workflow design, release planning, QA collaboration, Agile/Scrum, Jira, Confluence, SharePoint, technical documentation.
Rust, WebAssembly, Sycamore, GitHub; ChatGPT, Claude, Gemini; structured multi-model workflows for research synthesis, requirements, critique, implementation support, QA, documentation, evaluation, and verification.
Lab usability testing, think-aloud protocols, benchmarking and A/B testing, cognitive and pluralistic cognitive walkthroughs, contextual inquiry, ethnographic field research, focus groups, paper prototyping, interactive prototyping (including Macromedia Director), Net Promoter Score (NPS) research, large-sample surveys, formal experimental design and Human Factors research, analytical decision-making, data quality and validation, Microsoft Excel, Tableau, working familiarity with SQL and Power Query/M, open-data publishing.