Engineering joy: Building the celebration system on the Home tab of the LINE app on Android

&OHJOFFSJOH+PZ #VJMEJOH-*/&T"OESPJE$FMFCSBUJPO4ZTUFNBU4DBMF -:$PSQPSBUJPO -*/&"QQ%FW 5VBO 5VOB

"OESPJE4PGUXBSF&OHJOFFS 8PSLJOHPO-*/&T)PNFUBCGFBUVSFT 1BTTJPOBUFBCPVUCVJMEJOHEFMJHIUGVMVTFS FYQFSJFODFT "CPVUNF

4IPXDBTF 5IF$IBMMFOHF 4ZTUFN"SDIJUFDUVSF0WFSWJFX *NQMFNFOUBUJPO%FFQ%JWF #VJMEJOH#MPDLT4ZOFSHZ 3FTVMUT*NQBDU 2VFTUJPOT%JTDVTTJPO "HFOEB

#JSUIEBZ$ISJTUNBT $FMFCSBUJPOT -*/&"QQ)PNFUBCEVSJOH

5IF$IBMMFOHF 1SFDJTJPO5JNJOH &WFOUTNVTUUSJHHFSFYBDUMZXIFOJOUFOEFE TVSWJWJOHBQQSFTUBSUT 3FTPVSDF.BOBHFNFOU &GGJDJFOUIBOEMJOHPGDFMFCSBUJPOBTTFUTBDSPTTNJMMJPOTPGEFWJDFT &EHF$BTFT
/FUXPSLGBJMVSFT BQQUFSNJOBUJPOT NVMUJQMFDPODVSSFOU DFMFCSBUJPOT

0VS4PMVUJPO 3FMJBCMF.BHJD #VJMEJOH#MPDLT 1IBTF"SDIJUFDUVSF

4ZTUFN"SDIJUFDUVSF0WFSWJFX

#VJMEJOH#MPDLT'PVOEBUJPO 3PPN%BUBCBTF 3FMJBCMFMPDBMTUPSBHFXJUISFBDUJWFRVFSJFT 8PSL.BOBHFS 1SFDJTFTDIFEVMJOHBDSPTTBQQMJGFDZDMF ,PUMJO'MPX 3FBDUJWF6*VQEBUFTBOETUBUFNBOBHFNFOU

1IBTF+PVSOFZ &WFOU %JTDPWFSZ 3FTPVSDF "DRVJTJUJPO 4IPX5JNF $MFBO6Q 3FDFJWFFWFOU OPUJGJDBUJPO %PXOMPBEFWFOU
NFUBEBUB %PXOMPBEBOEWBMJEBUF SFTPVSDFT %JTQMBZFGGFDUTBU UIFEFTJHOBUFEUJNF $MFBOVQSFTPVSDFT 4DIFEVMFOFYU PDDVSSFODF .BJOUBJOSFBEJOFTT EVSJOHJEMFQFSJPET

,FZ%FTJHO1SJODJQMFT EBZQSFQBSBUJPOCVGGFSFOTVSFTSFMJBCMFEFMJWFSZ $MFBSTFQBSBUJPOPGDPODFSOTCFUXFFOQIBTFT *OEFQFOEFOUFSSPSIBOEMJOHJOFBDIDPNQPOFOU 6TFSDFOUSJDUJNJOHXJUIHSBDFQFSJPET

*NQMFNFOUBUJPO%FFQ%JWF +PVSOFZ5ISPVHI"MM'PVS1IBTFT

1IBTF&WFOU%JTDPWFSZ $MJFOU TJEF 4FSWFS QVTIFE scheduledTime = showTime - 5
days retryUntil = showTime + 1 day 8PSL.BOBHFS {showTime} .FUBEBUB%PXOMPBE8PSLFS {showTime}

1IBTF3FTPVSDF"DRVJTJUJPO .FUBEBUB 'FUDIJOH "TTFU %PXOMPBE retry retry %POF

3PCVTU*NQMFNFOUBUJPO // Metadata Download Worker: Fetch event configurations if (retryUntil
< now) { return failure() } val event = fetchEventMetadata(eventId) // error -> retry saveEventMetadata(event) // error -> retry scheduleAssetDownload(event) // success -> next step .FUBEBUB%PXOMPBE8PSLFS'FUDIFWFOUDPOGJHVSBUJPOT

3PCVTU*NQMFNFOUBUJPO // Asset Worker: Download and validate celebration assets if
(retryUntil < now) { return failure() } val asset = downloadAsset(event) // error -> retry validateAsset(asset, event.checksum) // error -> retry fileStorage.extractAndSave(eventId, asset) // error -> retry // success scheduleShowtime() scheduleCleanup() "TTFU8PSLFS%PXOMPBEBOEWBMJEBUFDFMFCSBUJPOBTTFUT

1IBTF3FTPVSDF"DRVJTJUJPO .FUBEBUB 'FUDIJOH "TTFU %PXOMPBE retry retry %POF 4DIFEVMJOH 4IPXUJNF
4DIFEVMJOH $MFBOVQ WorkManager 3PPN%#

1IBTF4IPX5JNF 1&/%*/( 3&"%: '6--@4$3&&/@ &''&$5@$0.1-&5& % "MM#VJMEJOH#MPDLT6OJUF

&MFHBOU4JNQMJDJUZ // WorkManager: One simple state change eventRepository.updateEventState(eventId, READY) //
Everything else happens automatically: // Room → Flow → UI updates seamlessly

1FSGFDU$PMMBCPSBUJPO 8PSL.BOBHFS5SJHHFSTUIFQSFDJTFNPNFOUXJUIPOFMJOFPG DPEF 3PPN3FBDUJWFEBUBCBTFJOTUBOUMZOPUJGJFTBMMPCTFSWFST 'MPX)BOEMFTDPNQMFYQSJPSJUZ UJNJOH BOE6*DPPSEJOBUJPO
BVUPNBUJDBMMZ

1IBTF$MFBO6Q EBZHSBDFQFSJPE QSFWFOUTJOUFSSVQUJPOGPSMBUFVTFST $PNQSFIFOTJWFSFNPWBM PGBTTFUTBOENFUBEBUB 3FDVSSJOHFWFOUT BVUPNBUJDBMMZSFTDIFEVMFOFYUPDDVSSFODF
&GGJDJFOU3FTPVSDF.BOBHFNFOU

1IBTFNBQ 1IBTF 1IBTF retry 1IBTF 1IBTF

#VJMEJOH#MPDLT4ZOFSHZ $PNQMFY4UBUF.BOBHFNFOU.BEF4JNQMF

5IF1PXFSPG*OUFHSBUJPO 8PSL.BOBHFSTDIFEVMFT 3PPNTUPSFTRVFSJFT 'MPXSFBDUT 6*VQEBUFT

3FBM*NQBDU$PNQMFY-PHJDJO4JNQMF$PEF // All three building blocks working together: val displayableEventFlow
= combine( homeEventEffectDao.getDisplayableEventsFlow(), // Room: reactive queries homeTabVisibilityFlow // Flow: UI state tracking ) { events, isHomeVisible -> events.takeIf { isHomeVisible } // Timing: only when visible ?.maxByOrNull { it.priority } // Priority: personal > cultural } // Worker updates Room → Room triggers Flow → Flow updates UI displayableEventFlow.collect { event -> showEffect(event) }

8IBU5IJT"DIJFWFT $PNQMFYDPPSEJOBUJPOCFDPNFTEFDMBSBUJWFQSPHSBNNJOH .VMUJQIBTFTUBUFUSBOTJUJPOTIBOEMFEBVUPNBUJDBMMZ &SSPSSFDPWFSZBDSPTTQIBTFT XJUITJOHMFSFUSZTUSBUFHZ 3FBDUJWF6*VQEBUFTFMJNJOBUF
NBOVBMTUBUFTZODISPOJ[BUJPO 3FTVMU$PNQMFYDFMFCSBUJPOPSDIFTUSBUJPO ˠ4JNQMFSFBDUJWFEFDMBSBUJPOT

3FTVMUT*NQBDU

1FSGPSNBODF"DIJFWFNFOUT DFMFCSBUJPOEFMJWFSZ 4VDDFTTSBUF JNQBDU "QQTUBSUVQ ;FSP EVSJOHJEMFQFSJPET 3FTPVSDFTGPPUQSJOU -PX

"VUPNBUJDSFDPWFSZ GSPNOFUXPSLGBJMVSFTBOEBQQDSBTIFTPSSFTUBSUT 5FDIOJDBM&YDFMMFODF PGCVJMEJOHCMPDLTGPSDPNQMFYTUBUFNBOBHFNFOU 4FBNMFTTJOUFHSBUJPO TJNQMJGJFTRVBMJUZBTTVSBODF *OEFQFOEFOUQIBTF UFTUJOH

1FSGFDUUJNJOH DSFBUFTHFOVJOFTVSQSJTFNPNFOUT 6TFS&YQFSJFODF FOTVSFTCJSUIEBZTBSFOUNJTTFECZIPMJEBZT 1FSTPOBMQSJPSJUZ FOIBODFFNPUJPOBMJNQBDU $VMUVSBMBXBSFOFTT FOIBODFFNPUJPOBMJNQBDU 4NPPUIBOJNBUJPOT

,FZ5BLFBXBZT

"SDIJUFDUVSF-FTTPOT 4USBUFHJDQSFQBSBUJPO EBZCVGGFS QSFWFOUTMBTUNJOVUF GBJMVSFT 1IBTFJTPMBUJPO FOBCMFTJOEFQFOEFOUFSSPSIBOEMJOHBOEUFTUJOH
#VJMEJOHCMPDLTZOFSHZ MFWFSBHFT"OESPJETTUSFOHUITFGGFDUJWFMZ 6TFSDFOUSJDEFTJHO USBOTGPSNTUFDIOJDBMDPOTUSBJOUTJOUP EFMJHIUGVMFYQFSJFODFT

*NQMFNFOUBUJPO*OTJHIUT &BSMZSFTPVSDFBDRVJTJUJPO FOTVSFTSFMJBCMFDFMFCSBUJPOEFMJWFSZ 3FBDUJWFTUBUFNBOBHFNFOU UISPVHI'MPXTJNQMJGJFTDPNQMFY6* DPPSEJOBUJPO 8PSL.BOBHFSTDIFEVMJOH
DPPSEJOBUFTQSFDJTFQIBTFUSBOTJUJPOT BOESFUSZMPHJD 3PPNTSFBDUJWFRVFSJFT QSPWJEFSFBMUJNFTZTUFNTUBUF BXBSFOFTT

5IBOL:PV

&OHJOFFSJOHKPZ#VJMEJOHUIFDFMFCSBUJPOTZTUFN POUIF)PNFUBCPGUIF-*/&BQQPO"OESPJE IUUQTUFDICMPHMZDPSQDPKQFOFOHJOFFSJOHKPZCVJMEJOHUIFDFMFCSBUJPOTZTUFNPOUIF IPNFUBCPGUIFMJOFBQQPOBOESPJE ,PUMJO'MPX%PDVNFOUBUJPO IUUQTLPUMJOMBOHPSHEPDTGMPXIUNM 3PPN%BUBCBTF%PDVNFOUBUJPO
IUUQTEFWFMPQFSBOESPJEDPNUSBJOJOHEBUBTUPSBHFSPPN 8PSL.BOBHFS%PDVNFOUBUJPO IUUQTEFWFMPQFSBOESPJEDPNUPQJDMJCSBSJFTBSDIJUFDUVSFXPSLNBOBHFS 3FGFSFODFT

Engineering joy: Building the celebration syste...

Engineering joy: Building the celebration system on the Home tab of the LINE app on Android

Transcript

More Decks by LINEヤフーTech (LY Corporation Tech)

Other Decks in Technology

Featured