FRACTIONAL PRODUCT LEADERSHIP · AI · FINTECH · DIGITAL PRODUCTS

Clear thinking for
better products.

I provide hands-on fractional product leadership for AI, fintech, and digital teams. I help clarify priorities, strengthen requirements, and turn product uncertainty into shipped progress.

I help founders and product teams decide what to build, structure the work, and move from product uncertainty to useful products.

Book a 30-minute product conversation No sales pitch. Click to schedule via Google Calendar or scroll below to use the live embedded calendar.
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Led by Karina Mashkantseva · AI Product Manager · Former FNZ Product Owner · Founder & Product Lead at StensWay ★ Work directly with Karina from discovery to delivery.
Where good product decisions meet
User Value
Business Goals
Technical Feasibility
Prioritized Outcomes
"Clarity is a delivery advantage." ➔
⬑ "Prioritisation is saying no to good ideas."
Where good product decisions meet:
● User Value ● Business Goals ● Technical Feasibility ★ Prioritized Outcomes
"Clarity is a delivery advantage."
FNZ Wealth Platform
Product Owner · Core wealth-planning tools
Goal Planner · Portfolio Optimiser · Cashflow Planner
StensWay Platform
Founder & Product Lead · Concept to live launch
AI-Enabled Coaching Platform · ~30 Core Workflows
Reliable Delivery
Quality engineering & release confidence
ISTQB & CSPO Rigor · Business Rules Validated
WHEN PRODUCT WORK GETS STUCK

Is your product work stuck in ambiguity?

You have a product to build, but the next decision is unclear. I help you decide what matters, structure the work, and move the team forward.

FOR STARTUPS & FOUNDERS

For founders and small teams that need to clarify an MVP, prioritise the roadmap, or establish a practical product operating rhythm.

FOR MID-SIZED COMPANIES

For product and engineering teams that need temporary product ownership, clearer requirements, better delivery coordination, or support on a complex initiative.

01 // ROADMAP PARALYSIS

Too many ideas, no clear priority.

Customer requests, investor feedback, and internal brainstorms compete for developer attention. Sprints drift without an explicit decision on what not to build right now.

02 // SPECIFICATION CHURN

Engineering is building, but requirements keep changing.

Developers hit hidden edge cases halfway through implementation. Rework multiplies, estimates slip, and engineers become frustrated translating vague briefs into production code.

03 // SCOPE INFLATION

Your MVP is expanding before the core journey works.

Features keep getting added before the primary user loop is proven with real data. You spend months building peripheral functionality while the core monetization journey stays unverified.

04 // LEADERSHIP GAP

You need product ownership before hiring full-time.

Hiring a full-time CPO takes 3–6 months and requires substantial equity and executive salary. You need immediate, disciplined product ownership to ship this quarter's milestones.

✕ Casta Product may not be the right fit if you are looking for:
  • A software development agency. I provide hands-on product leadership, discovery, and requirements ownership—not an outsourced dev shop.
  • Someone to replace your entire engineering team. I partner with your existing engineers and designers to make their work clear and actionable.
  • A strategy deck without delivery involvement. I stay close to the work, the backlog, and the sprint execution.
  • Guaranteed growth without access to users, data, or the team. Real product progress requires direct access to reality, metrics, and team collaboration.
SERVICES & PRICING

Ways to work together.

Practical product leadership with transparent pricing and clear outcomes. Every format is designed to unblock engineering and give you immediate momentum.

90-Minute Working Session

Product Decision Session

Focus: Decide on a critical product fork or bottleneck. Ideal for founders facing an urgent scoping dispute or stalled feature priority.

Result: Leave with a clear Decision Memo and prioritised next-step plan.
  • Pre-session audit of your current roadmap, backlog, or blocker
  • 90-minute structured trade-off & prioritization session
  • Written Decision Memo delivered within 48 hours
  • Prioritised next-step plan engineering and founders can act on
Investment €300 one-time Founding client rate (first 5 sessions) · Standard €450
Book a 30-minute product conversation ↗
2-Week Focused Sprint · 10 Business Days Most Popular

Product Clarity Sprint

Focus: Decide what to build and why. Ideal for scoping an MVP, major workflow, or complex AI/fintech feature before engineering starts.

Result: Leave with a focused MVP or next-release decision.
  • Complete Product Requirements Document (PRD) with edge-case mapping
  • Clickable low-fidelity user flow wireframes & information architecture
  • Prioritized user story backlog with clear acceptance criteria
  • Technical feasibility alignment session with your engineering lead
Fixed Investment €2,800 fixed fee
Book a 30-minute product conversation ↗
4-Week Embedded Sprint

Product Delivery Setup

Focus: Make it buildable and testable. Ideal for teams where engineering velocity is bogged down by vague tickets or sprint rework.

Result: Leave with work engineering and QA can act on.
  • Linear or Jira backlog cleanup, tag taxonomy & workflow setup
  • Definition of Ready (DoR) & Definition of Done (DoD) implementation
  • QA verification protocols & acceptance criteria templates
  • Sprint rhythm templates: planning, backlog refinement & retros
Fixed Investment €4,900 fixed fee
Book a 30-minute product conversation ↗
Ongoing Retainer · 1–2 Days / Week

Fractional Product Management

Focus: Stay involved while the team delivers and learns. Experienced product leadership embedded directly in your team without executive overhead.

Result: Maintain product momentum through an ongoing operating rhythm.
  • Dedicated product ownership embedded directly in your Slack & Linear
  • Running sprint planning, refinement, and delivery reviews
  • Direct liaison between founders, engineering, and stakeholders
  • Structured roadmap prioritization and regular release tracking
Starting Investment From €3,500 / month
Book a 30-minute product conversation ↗

Not ready to book a conversation?

Download the free 10-point Product Readiness Checklist to evaluate your roadmap health, specification readiness, and sprint alignment before reaching out.

DISCIPLINED METHODOLOGY

How I move from uncertainty to shipped progress.

A battle-tested four-stage rhythm that replaces guesswork with verified evidence and disciplined engineering execution.

STAGE 01

Understand

I evaluate the problem space, commercial context, technical constraints, and real user friction before writing a single spec.

Key Artifact Problem Diagnostic & Constraint Matrix
STAGE 02

Focus

I help make the hard trade-offs, cutting through distractions to isolate the critical user journey that creates measurable business value.

Key Artifact Prioritized Scope & Decision Memo
STAGE 03

Structure

I translate priorities into clear specifications, edge-case maps, and acceptance criteria that engineering teams can build without hesitation.

Key Artifact Structured PRD & Backlog
STAGE 04

Learn

I verify shipped releases against real usage feedback, review delivery metrics, and feed objective insights directly into the next sprint iteration.

Key Artifact Release Review & Sprint Retro
SELECTED WORK & DELIVERY TRACK RECORD

Concise case studies from real products.

From complex calculation engines within the FNZ wealth platform to building an AI-enabled coaching platform from concept to launch.

FNZ
Product Owner

Regulated Wealth-Management Products · Institutional Financial Services

Product Owner for core wealth-planning tools.

Context: Regulated wealth-management products within the FNZ enterprise platform.

Role: Product Owner for Goal Planner, Portfolio Optimiser, and Cashflow Planner.

Contribution: Backlog, epics, stories, acceptance criteria, business rules, integrations, testing, and delivery sequencing.

Evidence: Approximately 900 test cases, around 100 defects resolved, and roughly 10 APIs/integrations validated.

3 Planning Tools Goal Planner, Portfolio Optimiser & Cashflow Planner
~10 Integrations Platform integrations and calculation APIs validated
StensWay
Founder & Product Lead

AI-Enabled Coaching & Personal Development Platform

Built from concept to live AI-enabled coaching platform.

Context: AI-enabled coaching and personal-development platform.

Role: Founder and Product Lead.

Contribution: Product discovery, user journeys, MVP prioritisation, workflow design, automation, and release testing.

Evidence: Designed multi-tenant journeys for clients, coaches, corporate stakeholders, and administrators, and shipped approximately 30 core workflows and automations.

~30 Core Workflows Multi-tenant client, coach, and corporate automations
0 to 1 Launch Full product lifecycle from concept to live operational platform
Quality Engineering
CSPO & ISTQB Certified Rigor

Acceptance Criteria · Defect Resolution · Release Confidence

Reliable delivery through structured verification.

Context: High-stakes product environments where release failures cost money and reputation.

Role: Certified Scrum Product Owner (CSPO) and ISTQB Certified Tester.

Contribution: Defining clear acceptance criteria, comprehensive test scenarios, and edge-case validation before engineering begins.

Evidence: Reliable delivery — business rules, acceptance criteria, API behaviour, and edge cases validated before release.

~100 Defects Resolved Critical functional defects resolved prior to production release
Reliable Delivery Business rules, acceptance criteria & edge cases verified pre-release
Experience includes work at FNZ and the independent development of StensWay. References are descriptive of past operator roles and do not imply corporate endorsement.
Book a 30-minute product conversation ↗ No sales pitch. We’ll clarify your product challenge and determine whether I can help.
Karina Mashkantseva, Fractional Product Manager

Karina Mashkantseva

AI Product Manager · Fractional Product Lead
  • AI Product Manager & 0-to-1 Founder (StensWay)
  • Former Platform Product Owner, FNZ WealthTech
  • Certified Scrum Product Owner (CSPO)
  • ISTQB Certified Quality Engineering Rigor
  • Based in Thessaloniki, Greece (CET / EET / GMT)
DIRECT OPERATOR PARTNERSHIP

Work directly with Karina from discovery to delivery.

When you engage Casta Product, you work directly with me. You won't be passed off to junior associates, outsourced analysts, or an agency account manager.

I integrate straight into your existing communication cadence—joining your Slack, collaborating in Linear or Jira, and writing tickets your developers can pick up without ambiguity. Having built an AI-enabled coaching platform from zero as a founder and managed platform tools in enterprise wealthtech at FNZ, I understand both the urgency of startup delivery and the rigor required for enterprise scale.

"Good product management isn't about producing endless documentation. It's about giving engineering the clarity they need to ship the right thing the first time."
Book a 30-minute product conversation ↗ No sales pitch. We’ll clarify your product challenge and determine whether I can help.
LIVE APPOINTMENT SCHEDULER

Book a 30-minute product conversation.

No sales pitch. Select a convenient time below on Google Meet to clarify your product challenge and determine whether I can help.

Live Availability · Google Meet Video Conference
Open in Google Calendar ↗
Need a time outside these slots or prefer to send project details in advance?
FREQUENTLY ASKED QUESTIONS

Everything you need to know.

Direct answers on engagement structure, communication tools, and time commitments.

How does fractional product management differ from a full-time CPO hire?
A full-time CPO typically costs €120k–€180k+ in annual salary plus equity and takes months to recruit. A fractional engagement gives you immediate, senior hands-on product ownership (1–2 days/week) focused exclusively on unblocking engineering, structuring backlogs, and writing clear requirements without executive overhead.
Which communication and management tools do you work with?
I embed directly into your existing stack—most commonly Slack for asynchronous updates, Linear or Jira for backlog management and sprint tracking, Notion or Confluence for PRDs, and Figma for wireframe reviews.
What stage of company is the best fit for Casta Product?
I primarily work with early-stage to growth startups, bootstrapped digital businesses, and fast-moving AI or fintech teams with 3 to 15 engineers where founders need experienced product leadership to unblock delivery and maintain shipping momentum.
What are your working hours and time zone availability?
I am based in Thessaloniki, Greece, operating comfortably across Central European Time (CET), Eastern European Time (EET), and Greenwich Mean Time (GMT), offering real-time overlap with London, Berlin, Athens, and US East Coast mornings.
How do we handle IP and confidentiality?
All proprietary code, roadmaps, customer data, and requirements written during the engagement remain 100% your intellectual property. A mutual non-disclosure agreement (NDA) is signed prior to starting any sprint or fractional role.