What I've Learned Doing Over 100 Website Replatformings and Migrations

Every migration checklist says to crawl, map redirects, and launch. The migrations that go wrong at capable companies rarely skip a checklist item. They fail on what a checklist doesn’t test: a redirect that returns a 200 instead of a 301, a 302 left in place for years, and internal links that quietly rewire when the new platform ships.

After 100+ replatformings, consolidations, and restructures, I’ve watched the same failures repeat. In 25 minutes, I’ll walk through the real cases behind them, including a homepage that took 40% of clicks away from the right URL, and a site-wide 302 that cost rankings until it became a 301. You’ll leave with three things you can use on your next project:

A request-level way to verify redirects, so you see what Googlebot sees instead of what your browser shows you
A method for mapping redirects on large sites with no clear URL patterns, using vector embeddings for a first pass and people and rules for the final call
A way to score internal link equity on staging before launch, so you can fix lost and orphaned pages while it is still cheap

I’ll also cover how to monitor the traffic shift after launch, and where to compromise with developers and designers and where to hold the line.

Transcript

1. What I’ve Learned Doing Over 100 Website Replatformings, Migrations, and Consolidations Zach Chahalis VP of Relevance Engineering & Analytics iPullRank X: @ZachChahalis LI: /zacharychahalis
2. I’M ZACH CHAHALIS VICE PRESIDENT OF RELEVANCE ENGINEERING & ANALYTICS iPullRank My context: 16 Years in SEO, Marketing Analytics, and CRO 1 Year at iPR (But 3 yrs in total) 11 Yr Old Goldendoodle and 4 Yr Old Aussiedoodle Married Just Over Six Months
3. NOW I’M NOT GOING TO BATTLE KRISHNA ON CATS VS DOGS 3
4. BUT I AM GOING TO USE MY PUP TO HELP ME DISCUSS REPLATFORMINGS 4
5. MEET RUGER My (obnoxiously and adorably) expressive goldendoodle.
6. IT DOESN’T TAKE MUCH TO COMPLETELY THROW YOUR MIGRATION OFF THE TRACKS 6
7. BRING YOUR TEAM IN AT THE RIGHT TIME THIS IS WHAT A CLIENT’S RANKINGS LOOKED LIKE WHEN THEY CAME TO ME A YEAR AFTER LAUNCHING Launch “Maybe we should get help”
8. RUGER ACCURATE REFLECTS HOW I’M FEELING IN THIS MOMENT
9. SO WE NEED TO BE INVOLVED FROM THE START IF WE WANT TO BE SUCCESSFUL 9
10. OTHERWISE, WE’RE HANGING ON FOR DEAR LIFE (Ruger was not a fan of having a coupe)
11. A SITE MOVE IS 11 STEPS THE WELL-PAVED PROCESS 1 2 3 4 Decide what content moves Map old URLs to new URLs Map broken links to new URLs Move the content 8 7 6 5 Publish new XML sitemaps Update canonical tags, sitemaps Point links at final URLs Redirect old URLs to new URLs 9 10 11 Crawl old URLs, validate redirects File Change of Address in GSC Watch rankings, analytics, logs Source: Google Search Central, site moves with URL changes Plan Build Verify and watch
12. BUT LET’S DISCUSS SOME THINGS I DON’T SEE DONE OFTEN ENOUGH 12
13. NOT CHECKING HEADER RESPONSES OR DOING CURL REQUESTS 13
14. A RECENT SITE AUDIT TURNED UP DUPLICATE HOMEPAGES IN GSC COMPETING FOR CLICKS - EVEN TAKING 40% OF CLICKS
16. IT TOOK SOME TIME TO REPLICATE BUT THEN I ALSO FOUND IT IN THE WILD
17. BUT EVERY TIME I TESTED IT, I WOULD GET THE CORRECT HTTPS PAGE EVEN MULTIPLE TOOLS SHOWED NO ISSUE
18. SO I TRIED A CURL REQUEST IN MY TERMINAL FOR BOTH WWW AND NON-WWW http://www.website.com → HTTP/1.1 200 OK http://website.com → HTTP/1.1 200 OK
19. RELYING SOLELY ON HSTS WITHOUT A PROPER REDIRECT IT’S CERTAINLY AN OPTION… AS IS DISPLAYING A BLANK PAGE WITH THIS CONTENT…
20. THIS WAS THE CASE FOR EIGHT YEARS ALL HOMEPAGE TRAFFIC SHIFTED TO THE CORRECT PAGE AND THE HTTP PAGE DROPPED FROM THE INDEX
21. curl: one URL, every hop curl -sIL -A "Googlebot/2.1" http://facebook.com | grep -iE '^(HTTP|location)' HTTP/1.1 301 Moved Permanently location: https://facebook.com/ HTTP/2 301 location: https://www.facebook.com/ HTTP/2 200 EVERY HOP, EVERY URL Do not trust a redirect you have not requested. Walk the full chain, one request per hop, and read what each one returns. Consider running a curl request against key pages or use my free tool (hat tip to Patrick Schofield) Example From My Free Tool: https://header-checker.streamlit.app/
22. PROPERLY HANDLING AND MAPPING REDIRECTS 22
23. CONSIDER PRESERVING YOUR URLS WHENEVER POSSIBLE 23
24. REDIRECTS ARE VITAL KEEP THEM CLEAN 301, not 302 No chains Permanent moves pass authority. Use 302s only when truly temporary. Each hop wastes crawl budget and adds load time. Update legacy redirects to point at the final URL. Use rules, not rows Right status codes One wildcard rule beats thousands of lines, but test it. 404 or 410 when gone, never a soft 404, 503 for outages.
25. I WANT TO EMPHASIZE, THERE IS A PLACE AND SPACE FOR 302s… BUT IT ISN’T FOR A PERMANENT GLOBAL RULE IN A MIGRATION. THIS WAS IN PLACE FOR 8 YEARS!
26. DO YOU FEEL BONITA? IT LOOKS LIKE IT MIGHT WORK… BUT 302 REDIRECTING YOUR ENTIRE LEGACY SITE IS NOT BONITA (Ruger does not feel bonita here)
27. SWITCHING THE 302 TO A 301 BUT WE WERE TOLD THAT 302s WERE TREATED EQUALLY AFTER A WHILE…
28. WHAT ABOUT A LARGE WEBSITE WITHOUT CLEAR REDIRECT PATTERNS? 28
29. WE CAN USE VECTOR EMBEDDINGS TO AID IN REDIRECT MAPPING 29
30. A REDIRECT SHOULD LAND ON THE SAME MEANING NOT THE CLOSEST URL STRING BY URL STRING BY MEANING closest slug wins nearest vector wins Hand-mapping thousands of URLs doesn’t scale, and regex breaks when slugs and titles change. /mens-running-shoes/ /mens-running-shorts/ shorts closest string, wrong page /footwear/trail-runners/ right page, missed by string old nearest other Embeddings turn each page into a vector, so pages with the same meaning sit close together. For every old page, you find the nearest new page.
31. ONE METHOD: EXTRACT, EMBED, MATCH MIKE KING SHARED THIS APPROACH IN 2023 Source: iPullRank
32. TWO MODELS WORTH USING ONE LOCAL AND FREE, ONE HOSTED AND CHEAP
33. THE SCORE TELLS YOU WHO TO LOOK AT LOW SCORES GO TO A PERSON FOR REVIEW
34. EMBEDDINGS PROPOSE RULES AND PEOPLE DECIDE
35. TEST THE MODEL ON YOUR OWN PAGES TWO HUNDRED LABELED PAIRS BEAT ANY LEADERBOARD
36. LET THE MODEL DO THE FIRST PASS THEN VERIFY WITH REQUESTS
37. A FEW ADDITIONAL THINGS TO WATCH OUT FOR 37
38. DID YOUR MIGRATION CHANGE YOUR INTERNAL PAGERANK FLOW? 38
39. A MIGRATION CAN REWIRE YOUR LINKS SCORE YOUR LEGACY SITE AND YOUR DEV/STAGING SITE Internal PageRank models how link equity flows through your own site. Score a baseline crawl, then score staging and the live site. Use the redirect map to line up old pages with new ones. 1.0 means an average page, so you compare like with like.
40. FOUR THINGS THE SCORE CATCHES WHERE EQUITY MOVED 835 old pages compared: 29 lose equity, 17 are orphaned, 1 has no destination. The worst loser fell from an average page (1.0) to 0.16, with inlinks cut from 25 to 1.
41. RUN IT ON STAGING FIX THE LINKS BEFORE LAUNCH Crawl staging and compare it to your baseline. Fix losers, orphans and buried pages before go-live. Test a linking plan first, either your own changes or links the tool suggests for the pages you need to lift. It runs on two Screaming Frog exports and is free. Free Tool - https://website-pagerank-tool.streamlit.app/
42. DON’T FORGET TO MONITOR YOUR MIGRATION 42
43. YOU NEED TO MONITOR MIGRATION SUCCESS Do not trust a redirect you have not requested. Walk the full chain, one request per hop, and read what each one returns. Consider running a curl request against key pages
44. A URL CHANGE OR DOMAIN MIGRATION YOU NEED TO CLOSELY MONITOR THE TRAFFIC SHIFT Watch rankings, citation, analytics, and log files of both sites with the goal of seeing the target site overtake the source site’s rankings
45. MAKE SURE YOU UNDERSTAND HOW YOUR NEW PLATFORM WORKS 45
46. RTFM Know how the platform works and how to manage SEO components Know what’s not “out-of-the-box”
47. LEVERAGE A “DIRTY” XML SITEMAP AND INDEXNOW 47
48. USE A “DIRTY” XML SITEMAP TEMPORARILY Combine legacy crawls and your redirect map to create a sitemap of “old” URLs to submit to search engines Serve this file temporarily (a few weeks)
49. WORK WITH YOUR TEAM, NOT AGAINST THEM 49
50. THROW YOUR TEAM A BONE AND WORK TOGETHER Understand how to effectively prioritize your issues/stories and what is critical for launch. Say yes to the small stuff so you can hold the line on what matters. Learn to compromise.
51. COMPROMISE WITH DEV AND DESIGN BUT KNOW YOUR LINE YOU CAN COMPROMISE ON ❏ ❏ ❏ ❏ ❏ Post-launch title and meta rewrites Schema and alt text polish Casing and slash style (if consistent) Rule-based long-tail redirects Phasing low-traffic sections YOU ABSOLUTELY CANNOT ❏ ❏ ❏ ❏ ❏ 301s for every URL with traffic or links No staging noindex or Disallow live Canonicals and sitemaps on new URLs Same content and links without JS Rollback plan and post-launch monitoring RULE OF THUMB: Trade polish for launch dates, never crawlability for launch dates.
52. IF YOU DON’T REMEMBER ANYTHING ELSE… REMEMBER THESE FIVE THINGS Get SEO in the room before the platform is chosen. Redirects are your biggest opportunity and your biggest risk. Crawl and validate so you see what search engines see. Set benchmarks before launch and keep watching after. Work with developers and designers. Soft skills ship migrations.
53. HOPEFULLY THIS IS HOW YOU’LL NOW LOOK WHEN HANDLING YOUR NEXT REPLATFORMING PROJECT
54. THANK YOU Zach Chahalis Vice President of Relevance Engineering & Analytics iPullRank X: @ZachChahalis LI: /zacharychahalis Title Tap in with us: ipullrank.com What I've Learned Doing Over 100 Website Replatformings and Migrations Get the Slides: