Slide 1

Slide 1 text

Throw Away The Vibes: Context Engineering Is All You Need 21th Feb 2026 Dasith Wijesiriwardena @dasiths

Slide 2

Slide 2 text

I am here because I have a love hate relationship with distributed systems. HELLO! I AM Dasith @dasiths dasith.me

Slide 3

Slide 3 text

Context Engineering The Vibe Coding Problem Agenda Lessons & Patterns Why AI Coding Fails @dasiths

Slide 4

Slide 4 text

@dasiths “ ..Our philosophy is don't fix the code. Fix the context.. https://www.acquired.fm/episodes/how-is-ai-different-than-other-technology-waves-with-bret-taylor-and-clay-bavor https://sierra.ai

Slide 5

Slide 5 text

So, What’s the Problem With Vibe Coding? @dasiths

Slide 6

Slide 6 text

Promise vs Reality @dasiths

Slide 7

Slide 7 text

@dasiths

Slide 8

Slide 8 text

@dasiths ▪ It doesn’t work, I don’t know why. ▪ It works but I don’t know why. ▪ It works with my prompt. Growing Pains

Slide 9

Slide 9 text

@dasiths ▪ It doesn’t work, I don’t know why. ▪ It works but I don’t know why. ▪ It works with my prompt. Growing Pains

Slide 10

Slide 10 text

@dasiths ▪ It doesn’t work, I don’t know why. ▪ It works but I don’t know why. ▪ It works worked with my prompt. Growing Pains

Slide 11

Slide 11 text

@dasiths ▪ It doesn’t work, I don’t know why. ▪ It works but I don’t know why. ▪ It works worked with my prompt. Growing Pains

Slide 12

Slide 12 text

Looking at @dasiths

Slide 13

Slide 13 text

Coding Agents @dasiths “Senior implementation skills with junior design judgment” - Someone, 2025

Slide 14

Slide 14 text

Coding Agents @dasiths “Senior implementation skills with junior design judgment” - Someone, 2025

Slide 15

Slide 15 text

@dasiths https://blog.thepete.net/blog/2025/05/22/why-your-ai-coding-assistant-keeps-doing-it-wrong-and-how-to-fix-it/

Slide 16

Slide 16 text

@dasiths https://blog.thepete.net/blog/2025/05/22/why-your-ai-coding-assistant-keeps-doing-it-wrong-and-how-to-fix-it/ Granular tasks

Slide 17

Slide 17 text

Reality Check @dasiths

Slide 18

Slide 18 text

@dasiths

Slide 19

Slide 19 text

• Poisoning • Distraction • Confusion •Clash How Long Context Fails @dasiths https://www.dbreunig.com/2025/06/26/how-to-fix-your-context.html

Slide 20

Slide 20 text

Give your model the… > Right Context At the… > Right Time Let’s Fix Context @dasiths

Slide 21

Slide 21 text

Give your model the… > Right Enough Context At the… > Right Time Let’s Fix Context @dasiths https://blog.langchain.com/multi-needle-in-a-haystack/

Slide 22

Slide 22 text

Give your model the… > Right Enough Context At the… > Right Time Let’s Fix Context @dasiths https://www.youtube.com/watch?v=6_BcCthVvb8

Slide 23

Slide 23 text

Context Engineering @dasiths Foundations of

Slide 24

Slide 24 text

Context Engineering involves creating systems that provide the correct information and tools, in the proper format, exactly when needed, so that a large language model (LLM) has everything required to complete a task. The What? @dasiths https://www.philschmid.de/context-engineering

Slide 25

Slide 25 text

Context Engineering involves creating systems that provide the correct information and tools, in the proper format, exactly when needed, so that a large language model (LLM) has everything required to complete a task. The What? @dasiths https://www.philschmid.de/context-engineering

Slide 26

Slide 26 text

@dasiths

Slide 27

Slide 27 text

1. Write Context 2. Select Context 3. Compress Context 4. Isolate Context Core Tactics @dasiths https://rlancemartin.github.io/2025/06/23/context_engineering/ https://www.dbreunig.com/2025/06/26/how-to-fix-your-context.html

Slide 28

Slide 28 text

1. Write Context 2. Select Context 3. Compress Context 4. Isolate Context @dasiths https://rlancemartin.github.io/2025/06/23/context_engineering/ https://www.dbreunig.com/2025/06/26/how-to-fix-your-context.html Core Tactics

Slide 29

Slide 29 text

1. Write Context 2. Select Context 3. Compress Context 4. Isolate Context @dasiths https://rlancemartin.github.io/2025/06/23/context_engineering/ https://www.dbreunig.com/2025/06/26/how-to-fix-your-context.html Core Tactics

Slide 30

Slide 30 text

1. Write Context 2. Select Context 3. Compress Context 4. Isolate Context @dasiths https://rlancemartin.github.io/2025/06/23/context_engineering/ https://www.dbreunig.com/2025/06/26/how-to-fix-your-context.html Core Tactics

Slide 31

Slide 31 text

1. Write Context 2. Select Context 3. Compress Context 4. Isolate Context @dasiths https://rlancemartin.github.io/2025/06/23/context_engineering/ https://www.dbreunig.com/2025/06/26/how-to-fix-your-context.html Core Tactics

Slide 32

Slide 32 text

@dasiths

Slide 33

Slide 33 text

▪ Inconsistent Implementation – “The overeager intern” ▪ Knowledge Silos – “When the why is missing” ▪ Progress Fragmentation – “Worked with my prompt” @dasiths https://dasith.me/2025/04/02/vibe-coding-breadcrumbs/ The Misalignment Problem

Slide 34

Slide 34 text

The cost of this misalignment grows as development continues. ▪ Code reviews become more difficult ▪ Onboarding new team members takes longer ▪ The AI becomes less effective as a collaborator over time. @dasiths https://dasith.me/2025/04/02/vibe-coding-breadcrumbs/ The Misalignment Problem

Slide 35

Slide 35 text

The solution lies in creating an external, persistent shared context that both humans and AI can access and update. It’s a structured workflow consisting of… - Structured Planning & Task Management - Centralized & Accessible Knowledge Context - Living Documentation & Shared Understanding @dasiths https://dasith.me/2025/04/02/vibe-coding-breadcrumbs/ Solution: Breadcrumb Protocol

Slide 36

Slide 36 text

https://github.com/dasiths/VibeCodingBreadcrumbDemo

Slide 37

Slide 37 text

@dasiths Solution: Breadcrumb Protocol

Slide 38

Slide 38 text

@dasiths Research Embrace Plan Implement

Slide 39

Slide 39 text

AI coding assistants are brilliant at simple tasks and break everything they touch on complex ones. The root cause: AI can't tell the difference between investigating and implementing. When you ask for code, it writes code. It doesn't stop to verify that patterns match your existing modules or that the APIs it's calling actually exist. You: "Build me a Terraform module for Azure IoT" AI: immediately generates 2000 lines of code Reality: Missing dependencies, wrong variable names, outdated patterns, breaks existing infrastructure @dasiths Why Use RPI https://github.com/microsoft/hve-core/ Failure Mode

Slide 40

Slide 40 text

The solution isn't teaching AI to be smarter. It's preventing AI from doing certain things at certain times. This example RPI flow works by separating AI work into four distinct phases, each handled by a specialized agent: • Task Researcher: investigates your codebase and external sources, producing verified findings with citations • Task Planner: transforms research into actionable implementation plans with clear success criteria • Task Implementor: executes plans methodically, following established patterns discovered during research • Task Reviewer: validates implementation against specifications, checks compliance, and identifies follow-up work @dasiths Using RPI https://github.com/microsoft/hve-core/

Slide 41

Slide 41 text

• AVOID THE "DUMB ZONE. That’s the last ~60% of a context window. Once the model is in it, it gets stupid. Stop arguing with it. NUKE the chat and start over with a clean context. • SUB-AGENTS ARE FOR CONTEXT, NOT ROLE-PLAY. They aren't your "QA agent." Their only job is to go read 10 files in a separate context and return a one- sentence summary so your main window stays clean. • RESEARCH, PLAN, IMPLEMENT. This is the ONLY workflow. Research the ground truth of the code. Plan the exact changes. Then let the model implement a plan so tight it can't screw it up. • AI IS AN AMPLIFIER. Feed it a bad plan (or no plan) and you get a mountain of confident, well-formatted, and UTTERLY wrong code. Don't outsource the thinking. • REVIEW THE PLAN, NOT THE PR. If your team is shipping 2x faster, you can't read every line anymore. Mental alignment comes from debating the plan, not the final wall of green text. • GET YOUR REPS. Stop chasing the "best" AI tool. It's a waste of time. Pick one, learn its failure modes, and get reps. @dasiths Lessons From HumanLayer https://www.youtube.com/watch?v=rmvDxxNubIg

Slide 42

Slide 42 text

@dasiths “Harness Engineering” https://martinfowler.com/articles/exploring-gen-ai/harness-engineering.html

Slide 43

Slide 43 text

@dasiths https://blog.thepete.net/blog/2025/05/22/why-your-ai-coding-assistant-keeps-doing-it-wrong-and-how-to-fix-it/

Slide 44

Slide 44 text

@dasiths https://blog.thepete.net/blog/2025/05/22/why-your-ai-coding-assistant-keeps-doing-it-wrong-and-how-to-fix-it/

Slide 45

Slide 45 text

@dasiths Human

Slide 46

Slide 46 text

@dasiths “As we take charge of bridging the gap, the machine claims the praise.” > We Often Overestimate Machines and Undervalue Ourselves Using large language models (LLMs) for programming requires many supporting skills. However, these skills are not clearly defined and depend a lot on the situation, so right now, the best way to improve is through lots of practice and learning from mistakes. https://ferd.ca/the-gap-through-which-we-praise-the-machine.html

Slide 47

Slide 47 text

▪ Start with one context tactic and measure results ▪ Build systematic practices around context management ▪ Recognize context engineering as core technical skill @dasiths Practical Takeaways

Slide 48

Slide 48 text

▪ Start with one context tactic and measure results ▪ Build systematic practices around context management ▪ Recognize context engineering as core technical skill @dasiths Practical Takeaways

Slide 49

Slide 49 text

Context engineering is a systematic discipline Skilled practitioners will define the future of AI-assisted development @dasiths

Slide 50

Slide 50 text

Title Description URL [1] Pete Hodgson's Constraint-Context Matrix Primary problem framework https://blog.thepete.net/blog/2025/05/22/why-your-ai-coding-assistant-keeps-doing-it-wrong-and-how- to-fix-it/ [2] Drew Breunig's "How to Fix Your Context" Six practical tactics for context management https://www.dbreunig.com/2025/06/26/how-to-fix-your-context.html [3] Lance Martin's Context Engineering Four-strategy foundation https://rlancemartin.github.io/2025/06/23/context_engineering/ [4] Philipp Schmid's Context Engineering Context vs. prompt engineering distinction https://www.philschmid.de/context-engineering [5] Anthropic Research Context offloading (54% improvement) https://www.anthropic.com/engineering/claude-think-tool [6] "Less is More" Paper Smart tool selection (44% improvement) https://arxiv.org/abs/2411.15399 [7] Fred Hebert's Human-Machine Gap Operator skills importance https://ferd.ca/the-gap-through-which-we-praise-the-machine.html [8] Microsoft Azure CTO Warning Industry reality check on vibe coding hype https://www.geekwire.com/2025/reality-check-microsoft-azure-cto-pushes-back-on-ai-vibe-coding-hype- sees-upper-limit-long-term/ [9] Domain Understanding Requirement Context engineering needs domain expertise https://medium.com/@springrod/context-engineering-needs-domain-understanding-b4387e8e4bf8 [10] Breadcrumb Protocol Foundation workflow https://dasith.me/2025/04/02/vibe-coding-breadcrumbs/ [11] Manus Production Context Engineering Real-world lessons from building AI agents at scale https://manus.im/blog/Context-Engineering-for-AI-Agents-Lessons-from-Building-Manus References

Slide 51

Slide 51 text

Any questions? THANKS! @dasiths dasith.me https://www.nationalgeographic.com/travel/destinations/asia/sri-lanka/

Slide 52

Slide 52 text

No content

Slide 53

Slide 53 text

Presentation template designed by powerpointify.com Special thanks to all people who made and shared these awesome resources for free: CREDITS Photographs by unsplash.com Free Fonts used: https://www.fontsquirrel.com/fonts/oswald @dasiths